The Arsenal Files 8/The Arsenal Files Collection #8 (Arsenal Computer) (1996).ISO/hobby/x10faq.zip/X10.FAQ

Text File | 1996-05-19 | 141KB | 3,212 lines

<FAQ>

<FAQ NOTES>

 X10 FAQ version May 16, 1996

 To request a copy of the FAQ send email to [e-mail]
 or (preferred) get it from ftp://ftp.scruz.net/users/cichlid/public/x10faq

 To make a comment or submit some information for the FAQ send email to
 [e-mail]

 Many thanks to Tim Green the previous keeper of the FAQ.

 This FAQ is posted automatically the 1st and 15th of every month to
 comp.home.automation. Someday it will be formatted for posting in
 news.answers and will then be archived at rtfm.mit.edu.

</FAQ NOTES>

<FAQ CHANGES>

CHANGES SINCE LAST VERSION

Thanks to Neil Duffy for Q126 about X10 history.

</FAQ CHANGES>

<FAQ OUTLINE>

OUTLINE

SECTION 1:  General Information
Q101. What is X10?
Q102. What sort of X10 transmitters exist?
Q103. What sort of X10 receivers exist?
Q104. How many different units can X10 handle?
Q105. Who makes X10 components?
Q106. Who sells X10 components?
Q107. How do I solve common X10 problems?
Q108. Will X10 work on 220/240V?
Q109. How do I send and receive X10 signals with my computer?
Q110. Where do I get X10 software for my computer?
Q111. Where do I look for more information on X10?
Q112. How should I design the wiring of my new home to accommodate X10?
Q113. How do I control fluorescent and halogen lights with X10?
Q114. Can I use X10 in a three-way light switching application?
Q115. What is PLIX?
Q116. Can I use X10 components outside?
Q117. What are the various combinations of X10 wireless receivers and
      transmitters that work together?
Q118. How do I make the motion detector floodlight unit work properly?
Q119. How do I control an X10 device from a standard light switch?
Q120. How do I control my garage door with X10?
Q121. How do I improve the accuracy of my CP290 Home Control Interface?
Q122. How do I make an X10 light brighten up from zero intensity?
Q123. What components are available for me to build my own X10 modules?
Q124: What patents cover the X10 system?
Q125. What radio frequencies do X10 componants use?
Q126. Where did X10 come from?

SECTION 2:  Information on X10 Components

SECTION 3:  Details on X10 Protocol

SECTION 4:  Programming details for CP290 Home Control Interface

SECTION 5:  Modifications to X10 hardware

Q501. How do I modify appliance modules for momentary operation?
Q502. How do I add local dimming capability to wall switch modules?
Q503. How do I modify the maxi-controller to accommodate more than 16
      units?
Q504. How do I modify the mini-controller to control more units?
Q505. How do I modify the mini-controller to control all units for a
      single housecode?
Q506. How do I modify the mini-controller to control only units 9-12 or
      13-16?
Q507. How do I modify the mini-controller for momentary operation?
Q508. How do I repair a "blown" lamp module?
Q509. How do I defeat local control of lights and appliances?
Q510. How do I add a relay output to the power horn?
Q511. How do I change the crystal in my CP290?
Q512. How do I repair a broken wall switch module?

</FAQ OUTLINE>

<FAQ BODY>

<FAQ SECTION 1>

SECTION 1:  GENERAL INFORMATION
===============================


Q101. What is X10?

X10 is a communications protocol for remote control of electrical devices.
It is designed for communications between X10 transmitters and X10
receivers which communicate on standard household wiring. Transmitters and
receivers generally plug into standard electrical outlets although some
must be hardwired into electrical boxes. Transmitters send commands such
as "turn on", "turn off" or "dim" preceded by the identification of the
receiver unit to be controlled. This broadcast goes out over the
electrical wiring in a building. Each receiver is set to a certain unit
ID, and reacts only to commands addressed to it. Receivers ignore commands
not addressed to them.

Note that "X-10" is a trademark of X-10 (USA) Incorporated an possibly of
X-10 Home Controls Incorporated (in Canada) as well. This FAQ uses "X10"
unless referring specifically to a product of the holder of the "X-10"
trademark.

Q102. What sort of X10 transmitters exist?

The simplest X10 transmitter is a small control box with buttons. The
buttons select which unit is to be controlled, and which control function
is to be sent to the selected units (e.g. "turn on", "all units off", etc).
There are also clock timer transmitters which can be programmed to send X10
commands at certain times. Some of these can be programmed with buttons on
the timer; some must be connected to a computer to select the times. There
are other special purpose transmitters that send certain X10 commands at
sunup or sundown, upon detecting movement, or as commanded by tones over a
telephone. This is not an all inclusive list, and more detail on specific
transmitters is given in Section 2.


Q103. What sort of X10 receivers exist?

The simplest X10 receiver is a small module with an electrical plug (to
connect to a standard wall outlet), an electrical outlet (to provide
controlled power to the device it's controlling) and two dials (to set the
unit ID code) on it. An appliance module has relay inside which switches
power to its outlet on or off in response to X10 commands directed to it. A
lamp module is similar, but has a triac instead of a relay and will respond
to dimming commands as well as on or off commands. Other receivers can be
wired into wall outlets or into lamp fixtures. Note that the standard wall
switch (X10:WS467) is a receiver, not a transmitter; it does not transmit
X10 commands, and only takes action when it receives the appropriate X10
command or local button-push.


Q104. How many different units can X10 handle?

X10 specifies a total of 256 different addresses:  16 unit codes (1-16) for
each of 16 house codes (A-P). Normally a transmitter is set to a certain
house code (generally selectable by means of a dial) and so can control at
most 16 unit codes. There is no restriction on using multiple transmitters
each set to a different house code on the same wiring. Also, several
receivers could be set to the same house code and unit code so a single
command issued by an X10 transmitter could control multiple receivers in
parallel.


Q105. Who makes X10 components?

Many different companies either make and/or distribute X10 components
under different names. Some types are sold by more than one company
(probably made by same OEM). Some are specific to only one company. Not
all companies handle the complete range of components. Some companies
selling X10 components and their associated product names are:

 Radio Shack:
        Plug 'N Power

 Leviton:
        Decora Electronic Controls

        Leviton Mfg. Co. Inc.
        59-25 Little Neck Pkwy
        Little Neck, NY  11362-2591
        718-229-4040
        800-824-3005

        Leviton Manufacturing of Canada
        165 Hymus Blvd
        Point Claire, QC  H9R 1G2

 Stanley:
        Light Maker

 X-10:  Powerhouse

        X-10 (USA) Inc.
        91 Ruckman Road, Box 420
        Closter, NJ  07624-0420
        201-784-9700
        800-526-0027
        [e-mail]

        X-10 Home Controls Inc.
        1200 Aerowood Drive, Unit 20
        Mississauga, Ont  L4W 2S7
        416-624-4446
        800-387-3346

    X-10 Europe
    93 rue de Prony
    F-75017 PARIS
    FRANCE
        Voice 33-1-42678877
    Fax [phone]

 Home Automation, Inc.
    2709 Ridgelake Dr.
    Metairie, LA 70002
    Phone:   [phone]
    Fax:     [phone]

 Powerline Control Systems
    9031 Rathburn Avenue
    Northridge, CA 91325
    Phone: [phone]
    Fax:   [phone]


Q106. Who sells X10 components?

The following companies are alleged to sell X10 components in North
America. See Q108 for outside North America. Listing in this FAQ is not
an endorsement or recommendation of any kind:

If you are a dealer and wish to be listed here then please send me an
entry formatted _exactly_ like those below.

 Advanced Control Technologies
 Voice:  317-337-0100
 FAX:    [phone]

 Advanced Home Automation Inc.
 186 Raglan Road West
 Oshawa, ON
 Voice:   905-655-5355
 Orders:  800-265-6938
 Fax:     [phone]
 BBS:     905-655-5844

 Advanced Services Inc.
 4 South Russell Street
 Plymouth MA 02360
 Orders:  800-263-8608
 Voice:   508-747-5598
 Fax:     [phone]
 Email:   [e-mail]
 Web:     http://www.asihome.com

 Baran-Harper Group Inc.
 340A Alden Road,
 Markham, ON  L3R 4C1
 Help/Info:    905-946-2451
 Fax:          [phone]
 BBS:          905-479-0469

 Canadian Control and Automation Ltd
 7 Wincanton Rd.
 Markham, ON   L3S 3H3
 Phone:   [phone]
 FAX:     [phone]

 Complete Home Automation
 Phone:   [phone] (doesn't work in Canada)

 Home Automation Laboratories
 5500 Highlands Pkwy, Suite 450
 Smyrna, GA 30082-5141
 Orders:  800-466-3522
 Catalog: 800-935-4425
 Help:    404-319-6000
 Fax:     [phone] (is this the right number?)
          404-410-1122 (is this the right number?)
 BBS:     404-319-6227 (300-14.4,8,N,1)

 Home Automation and Security
 286 Ridgedale Ave.
 East Hanover, NJ 07936
 Orders:  800-254-5950
 Help:    201-887-1117
 Fax:     [phone]

 Home Automation Systems, Inc.
 151 Kalmus Drive, Suite M6
 Costa Mesa, CA 92626
 Orders:  800-762-7846 (doesn't work in Canada)
          800-367-9836 (supposedly works in Canada, but doesn't really)
 Help:    714-708-0610 (also for orders from outside US)
 Fax:     [phone]

 Home Control Concepts
 9520 Padgett St. Suite 108
 San Diego, CA 92126
 Orders:  800-422-4024
 Help:    619-693-8887
 Fax  :   [phone]

 Hybrid Technical Systems, Inc.
 4765 Franchise Street
 Charleston, SC 29418
 Orders:     800-289-2001 (doesn't work in Canada)
 America Online:  HybridTech
 Compuserve:    71561,2604

 JaMar Distributing
 1292 Montclair Drive,
 Pasadena, MD  21222
 Orders:     800-477-4181
 Fax:        [phone]
 Help:       410-437-4181

 JDS Technologies
 16750 W. Bernardo Drive
 San Diego, CA 92127
 Orders:     800-983-5537
 Help:       619-487-8787
 Fax:        [phone]

 Marrick Limited
 P.O. Box 950940
 Lake Mary, FL 32795
 Voice:      407-323-4467
 Fax:        [phone]
 BBS:        407-322-1429
 Email:      [e-mail]

 MicroMint
 4 Park St.
 Vernon, CT  06066
 Orders:     800-635-3355 (doesn't work in Canada)
 Phone:      [phone]
 Fax:        [phone]

 MoTron Electronics
 310 Garfield St., Suite 4
 PO box 2748
 Eugene OR 97402
 Tel:        [phone]
 Fax:        [phone]
 Orders:     800-338-9058

 Mountain Vista Supply, Inc.
 4108 La Linda Way
 Sierra Vista, AZ  85635
 Phone:      [phone]
 Fax:        [phone]

 Worthington Distribution
 36 Gumbletown Road
 Paupack, PA 18451
 and
 97 Fairmount Road
 Tewksbury, NJ 07830

 Orders: 800-282-8864
 Tech support: 717-226-8864
 Fax: [phone]
 Email: [e-mail]
 Web: http://www.hometeam.com/worthing.shtml


Q107. How do I solve the most common X10 problems?

There is a common problem that you may encounter in setting up your home
with X10 modules. This happens mostly in larger homes, say larger than
2000 square feet (185 square meters). The symptoms are that some receiver
modules may not work when commanded from some transmitters, or they may
only work sporadically.

This could be caused by too much isolation between the two sides of the
power line (assuming North American wiring standards):  a transmitter on
one side will not transmit reliably to a receiver on the other side. Try
your X10 system with and without your electric stove turned on; turning the
stove on may bridge both sides of the power line, but is not the
recommended permanent solution. A better way would be to install a signal
bridge which is available as a commercial product. See section 2 below for
details. An alternative solution is to install a 0.1 microfarad capacitor
(240 VAC or 600 VDC) across the 220 volt line "hot-to-hot". A qualified
electrician can do this across any 220 volt double pole breaker. This will
bridge the signal from one side to the other.

This could also be because the distance from the transmitter to the
receiver is too great and the signals are two weak to activate the
receiver. If moving the transmitter does not work or is not feasible, the
solution may be to install a signal amplifier. This is available as a
commercial product. See Section 2 below for details.

Noise blocks or noise filters may solve other more obscure problems (false
ON/OFF signals, for example), often caused by TVs or wireless intercoms.
Locate interference sources by unplugging them one at a time. See details
on commercially available noise blocks and filters in Section 2 below if
moving the transmitter away from interference sources does not work or is
not feasible.

> See next paragraph
> If a WALL OUTLET 220V, 15A (X10:HD243) or WALL OUTLET 220V, 20A (X10:HD245)
> doesn't seem to work in an apartment or office building, that may be
> because the building has a three phase power system and the X10 outlets are
> designed to work on a single (split) phase system such as found in a home.
> There is no solution to this.

New information (Jul 95). The X10 protocol apparently sends signals at
the zero crossing of the AC line voltage and then at 60 degrees and at
120 degrees after that (in other words, three times every half cycle
corresponding to the zero crossing of the other two phases). This is
designed to make X10 compatible with three phase power situations.

Some power strips that have filters in them to protect electronic equipment
effectively filter out X10 signals. Also appliances such as televisions
or other audio/visual equipment may have a capacitor across the AC line
to filter out high frequency noise. X10 signals appear as high frequency
noise to these capacitors and are thus attenuated. Cheaper power strips
that protect against voltage spikes only do not affect X10 signals. Try
moving X10 transmitters or receivers from power strips to a standard
outlet if they don't seem to be working.

Another common problem with X10 devices is not reading the documentation
that comes with them. People still insist on trying to use dimmer switches
or lamp modules on electric fans or fluorescent lights (symptom can be
fire), or trying to control low wattage lamps (symptom may be unreliable
operation for less than 50W for some modules). Solution:  RTFM. See also
Q113.


Q108. Will X10 work on 220/240V?

There are X10 receiver modules designed to control 240 volt loads, but only
where these are part of a standard North American wiring system, e.g. for
the electric stove or electric drier. See section 2 below.

Knowledge of how X10 works on anything else than 60 Hz 110V is a bit hazy
in North America. The following companies are reputed to sell X10 devices
for European use:

 Busch-Jaeger Elektro GmbH
 P.O. box 1280
 D-5880 Luedenscheid
 Germany
 Phone: [phone]
 Fax  : [phone]

 Celtel Ltd
 P.O. Box 135
 Basingstoke
 United Kingdom RG25 2HZ
 Phone:  [phone]
 Fax:    [phone]

 CAMEXCO Sweden HB
 Simborgarv=E4gen 27
 184 37  =C5kersberga
 Fax [phone]=20
 [e-mail]
 http://www.wineasy.se/kk/x10.htm

 Cirkit Distribution Ltd.
 Parks Lane
 Broxbourne, Herts
 United Kingdom EN10 7NQ
 Phone:   [phone]
 Fax:     [phone]

 Laser Business Systems Ltd.
 16, Garthland Drive
 Arkley, Barnet
 Hertfordshire EN5 3BB
 United Kingdom
 Tel: [phone]
 Fax: [phone]
 E-mail: [e-mail]
 http://www.io.com/~lbs/

 Smart House Systems
 3 Buchanan Street
 Largs,Ayrshire
 United Kingdom KA30 8PP
 Tel:   [phone]
 Fax:   [phone]

 WDC Home Automation
 30, The Broadway
 Thatcham, Berkshire
 United Kingdom RG13 4HX
 Phone:   [phone]
 Fax:     [phone]
 Email:   [e-mail]


The following companies are reputed to sell X10 devices in Australia:

 Brylyn Enterprises(Bryan Mason)
 Broadbeach, Queensland
 Phone:   [phone]

 CEBus Australia
 PO BOX 178
 Greensborough VIC 3088
 Australia
 Phone:   [phone]
 Fax:     [phone]

 Midac Technologies
 Upper Monkerai
 New South Wales 2415
 Australia
 Phone:   [phone]
 Fax:     [phone]

 The Smart Company
 5 Mouat Street
 PO Box 127
 Fremantle, Western Australia  6160
 Australia
 Phone:  [phone]
 Fax:    [phone]


Q109. How do I send and receive X10 signals with my computer?

The easiest way of giving your computer some control over X10 modules is
via the CP290 Home Control Interface. This is a small box that connects to
a standard RS-232 serial port and has its own internal battery backed up
seven day clock. It is sold with software to work with a PC, Mac, Apple ][,
or Commodore 64/128, and comes with the appropriate serial cable (the CP290
box itself is the same for all). Once you set up to 128 events (on, off,
dim) using your computer, you can turn off the computer and the box will
transmit scheduled X10 commands on a daily or weekly schedule. The CP290
also has an "immediate" mode to send X10 commands from the computer to X10
receivers. Details on programming the CP290 are in Section 4.

There are also other X10 modules to interface computers directly to the
power line to send and/or receive X10 commands. These are the PL513 (send
only) and the TW523 (send and receive).

The TW523 is a low level two-way interface to the power line. It
contains a PIC controller to decode incoming signals and store them for
transmission to the host computer. (The PIC is a family of
microcontrollers from Microchip Technology (before that, from General
Instrument).  They come in packages ranging in size from 18 pins up to
40 pins with a whole gamut of features.  They have nothing to do with
X-10 per se, but they work wonderfully for doing low-level X-10
control). It's essentially a 120KHz modulator and demodulator, with just
enough smarts to recognize a valid X-10 command code. Due to the tight
timing requirements and lack of drivers, applications are limited to
systems developers and experienced hobbyists willing to code in
assembly.

The computer interfaces to the TW523 through an RJ-11 modular phone jack
which has the following signals: signal (not AC) ground, receive output,
zero-cross output and transmit input. All signals are optocoupled, and the
outputs are open-collector. A logic high (greater than 4V) on the transmit
input modulates the AC line with the 120KHz carrier wave. The zero-cross
output is a square wave coincident with the 60Hz AC line. The receive
output is an envelope of the X-10 signal, and is low when the 120KHz signal
for `bit=1' is present during a valid code.

The signal applied to the transmit input must encompass all of the bits for
all 3 phases of the line (i.e. 3 bits per half AC cycle). The computer
must follow the full transmission protocol detailed in Section 3 of the
FAQ, but only needs to send the proper envelope for the transmission as the
TW523 converts the digital envelope into bursts of 120KHz carrier.

The receive output is buffered through the PIC in the TW523. The first
valid X-10 code cycle on the AC line alerts the PIC (and is lost to the
controlling computer). During the second code cycle (all codes in X-10
protocol are sent twice), the TW523 outputs a low when there is 120KHz
carrier on the AC line, and only during the bit time for the local AC
phase. The signals for the other two AC phases are not echoed to the
controlling computer. The output is open-collector at all other times.
The logic is reversed; when there's a valid `bit=1' (120KHz carrier), the
output is low, and high otherwise. Since the TW523 responds to all signals
on the AC line, it also echoes any sent by the controlling computer,
allowing for collision detection similar to that used by the Ethernet
protocol (CSMA/CD).

[Question: does it output only the second transmission when echoing local
transmissions?]

These units may be supplied with parallel or serial port adaptors. These
use handshaking bits in non-standard ways, so normal serial and parallel
port drivers are not of any use.

See also Q115 for information on PLIX, which simplifies interface
requirements considerably.


Q110. Where do I get X10 software for my computer?

The CP290 Home Control Interface comes with software for either IBM PC,
Mac, Apple ][, or Commodore 64/128. This is rudimentary, but functional.

Baran-Harper Group Inc in Ontario runs a bulletin board that has a good
selection of software for the CP290 and TW523. Their BBS number is 905-
479-0469. Also try BBS listed for other companies in Q106 above.

Other sources:

 FTP:  ftp.digibd.com/pub/rick/x10.shar
       oak.oakland.edu/SimTel/msdos/x_10/   (CP290)
       oak.oakland.edu/SimTel/win3/x_10/
       mrcnext.cso.uiuc.edu/asre/
       cs.sunysb.edu/pub/386BSD/xten.tgz
       id.wing.net/pub/pgf/x10/x10.tar.gz (UNIX CP290)
       pimacc.pima.edu/X10CMD    (CP290 source+ for VMS, Atari ST)
       ftp.cynus.com/pub/xmastree/x10.tar.gz (CP290 source)
       hydra.carleton.ca:/pub/x10/tw523.tar.gz(TW523)


 WWW:  http://www.digibd.com/people/rick
       http://web.cs.ualberta.ca/~wade/HyperHome/
       http://pimacc.pima.edu/~vcooper/   (CP290 source+ for VMS, Atari ST)


Q111. Where do I look for more information on X10?

Try the following:

Magazines:

 Circuit Cellar Ink
 4 Park St
 Vernon, CT  060663233
 Phone:   [phone]
 FAX:     [phone]
 BBS:     203-871-1988
 Email:   [e-mail]

 Electronic House [is this the editorial address???]
 EH Publishing
 P.O. Box 339
 Stillwater, OK 74076-9923
 Phone:   [phone]  [phone] ???
 FAX:     [phone]
 WWW:     http://www.hometeam.com/ehouse.shtml

 Electronic House [is this the address for subscriptions only???]
 P.O. Box 7972
 Riverton NJ 08077-8672
 Phone:   [phone]
 FAX:     [phone]

 Electronic House Magazine[...then what address is this???]
 304 Boston Post Road
 Wayland, MA 01778
 Phone:   [phone]
 Fax:     [phone]
 Email:   [e-mail]

 Home Automator
 2258 Sandy Lane
 Mebane, NC  27302
 Voice:   910-578 9519
 FAX:     [phone]
 Email:   [e-mail]
 Notes:   Free sample issue available, ask for it via voice, FAX or email.

 Practical Home Automation magazine
 3043 South Laredo Circle
 Aurora, CO USA 80013-1805
 Phone:   [phone]
 FAX:     [phone]
 BBS:     303-680-3864 (8N1, 2400-9600 V.32)

Books:

_The Complete Guide to Home Automation_ David Alan Wacker 1993 Betterway
Books Cincinnati, Ohio ISBN 1-55870-301-2. Review by Benjamin Lonske
follows.  Excellent introduction to Home Automation.  Chapters on
Wiring, X-10, Security Systems, Environmental Control, Whole House A/V,
Water Management, Whole House Automation, PC-Based Automation, SMART
HOUSE.  Good pictures and descriptions but not a how-to book.  One
negative: some descriptions about specific systems basically unfiltered
info from manufacturers.

_Controlling the World with Your PC_ by Paul Bergsman. About $30.
Discusses input and output interfacing through the parallel port, and
lots of things that you can then do to use that port to connect your PC
to the world.  It's available from Hightext, PO Box 1489, Solana Beach,
CA  92075, phone [phone].

_How to automate your home_ David Gladdis 2nd Ed. 1991 David
Gladdis(pub) ISBN 0-9632170-0-3. Available from Baran-Harper and
possibly other X-10 mail-order companies


Misc:

Electronic House publishes an annual resource guide listing many home
automation suppliers and manufacturers.

Some dated but still good information can be obtained by sending email
to [e-mail].

WWW:

Do a web search from your web browser for the latest sources.

 http://web.cs.ualberta.ca/~wade/HyperHome/
 http://www.ionet.net/hsn
 http://mmink.com/mmink/kiosks/x10/x10.html
 ftp://mrcnext.cso.uiuc.edu/asre/
 http://www.hometeam.com/ehouse.shtml
 http://www.hometeam.com/x10.shtml
 http://www.hometeam.com
 http://www.io.com/~lbs/

 These are not X10 but you probably want to know about them.

 http://su1.in.net/~cebus/homepage.htm
 http://www.lonworks.echelon.com

Mailing lists:

 The jds users mailing list is for users of JDS Timecommander and
 Homebase products to share experiences and information.  Send mail to
 [e-mail] with 'subscribe jds-users' unquoted in
 the body.

X10 Expertise for hire:

 Canadian Control and Automation Ltd
 7 Wincanton Rd.
 Markham, Ontario CANADA
 L3S 3H3
 Phone:   [phone]
 FAX:     [phone]
 Custom engineered home automation systems, security,fully distributed
 A/V, home theater, energy management solutions, also SmartHouse(tm)
 certified

 T. Brusehaver
 Empowered Home
 10608 Alabama Circle
 Bloomington, MN 55438
 Phone:   [phone]
 X10 hardware and software, development in other areas of home automation,
 energy saving devices, smart occupancy sensors, infrared control

 Rick Sloan
 IntelliHome Controls
 15 - 8 Deerfield Drive
 Nepean, ON, CANADA  K2G 3R6
 Phone:    [phone]
 FAX/BBS:  613-723-2370
 Net:      [e-mail]
 X10 hardware and software, development in other areas of home automation,
 energy saving devices,smart occupancy sensors, products for disabled
 persons, infrared control


Q112. How should I design the wiring of my new home to accommodate X10?

Most X10 receivers and transmitters can be plugged or wired into
conventional wiring in any home without any special preparation or design.
However, if you have the luxury of designing the wiring in your home before
it is built, there are a few things you may wish to consider.

A conventional light switch is wired into the circuit between the power
panel and the light it controls. Wiring conventional three-way (or more)
switches for use at the top and bottom of the stairs for example, takes
special wiring and foresight. There are X10 wall switches to replace
conventional switches in conventional wiring, both for simple on/off and
three-way control. See Q114.

You may wish, however, to put dedicated control modules (see LEV:6375,
LEV:6376 in Section 2) into built-in light fixtures and wire these fixtures
directly to the power supply with no conventional switch. You could then
turn the lights on or off from X10 transmitter anywhere in the house. Of
course, you may wish to put in a conventional switch somewhere so you could
manually enable/disable the light fixture independent of X10 on/off
control.

You would probably want to install wall mounted controllers (see LEV:6319
series) instead of light switches at convenient places like entrances or
stairways. The wiring for these wall mounted controllers is just like the
wiring for a power outlet: two wires direct to the power supply. This is
NOT the same as wiring for a conventional light switch. By changing the
settings on the control modules and the wall mounted controllers you can
link any switch to any light. Any light can be controlled in a three-way
(or four-way, or more) manner just by adding more wall mounted controllers
wherever convenient.

A motion/sunup/sundown detector (e.g. X10:PR511) is a good addition to any
house. You will probably want to wire this in a conventional circuit
controlled by a conventional light switch. This way you can disable it
(stop it from sending X10 signals) if you have to.

Other things you could consider are dedicated outlets in convenient
locations for Christmas lights (few house builders ever think of this).
This will avoid running extension cords out the garage or off the outdoor
light fixtures. With these controlled by X10, you could then have your
X10:CP290 turn them on or off as required. In Canada and other
occasionally frigid climates you might consider controlling the outlet for
your block heater by X10, but watch that the power drawn by the heater
doesn't exceed the capacity of the X10 receiver.

You may wish to document clearly how you have wired the house in case you
ever sell it. It may not be obvious to the next occupant, or to any
electrician he hires to "fix" things.

Don't forget telephone wiring. For the ultimate house, you'll want at
least one unlisted telephone line for remote control of your house from a
DTMF phone anywhere in the world. This will take a telephone interface
such as X10:TR551 or LEV:6325. While this might see like an expensive
luxury, think of what you could do by calling to turn off your fax machine,
and turn on your computer so that you could call it (on a separate line) to
transfer data. When done, you turn it off (or better, have it turn itself
off by sending the proper command to its X10 interface) and turn on the fax
machine again.

Also don't forget to allow for future expansion. Run empty conduit from
each room to a central location (AKA wiring closet). Class 125 PVC water
pipe is cheaper than Schedule 40 conduit. That way you can snake wires
to each room without climbing into the attic, under the house or running
wires under carpets, etc. Eventually you will want to add something new
(motion detectors and other security related items, temperature sensors,
computer networks, serial terminal lines, another phone line, TV,
speaker wires, etc etc etc). While you are at it, run a few 8 conductor
cables to each room. Terminate these cables and the conduit in a couple
of electrical outlet boxes with blank covers. X10 can't do everything :-)

See also: http://www.mcdata.com/~meh0045/homewire/wire_guide.html


Q113. How do I control fluorescent and halogen lights with X10?

Lamp modules and standard X10 wall switch (e.g. X10:WS467) generally do not
work well anything other than incandescent lights. There are several
reasons why this is so.

Both lamp modules and wall switches cut out part of the power sine wave to
dim the lights that are connected to them; the waveform available at the
load is no longer a simple sine wave, but a sharply-truncated version of a
sine wave. Even at full brightness, there is some power cut [Can anyone
confirm this?]. This is not too critical for a simple incandescent light.
For a compact fluorescent lamp that has some electronic circuitry in the
base to drive it, however, this is not a good idea since the circuitry is
designed around the expectation of a stable waveform at standard voltage.
Trying to dim a compact fluorescent by modifying the input power supply is
like trying to turn down the volume on your radio by putting it on a dimmer
circuit. It may sort of work with unpredictable results, but cause damage
to the load being dimmed.

Standard lamp modules and appliance modules have full access to house
current since they are plugged directly into a power outlet. Standard X10
wall switch modules, however, rely on getting their power from current
leaking through the filament of the incandescent bulb(s) in the circuit
they control even when the bulb is off. If the load they control is not a
standard incandescent bulb, there may be no (or not enough) current to the
switch and it may not operate as designed. This may be especially true for
fluorescent bulbs, or special power saving bulbs that have diodes built
into the base.

As noted above, the voltage output from lamp modules and standard X10 wall
switches is not a pure sine wave. Transformers are generally designed for a
certain frequency or range of frequencies (e.g. 50-60 Hz). They may not be
able to handle the higher frequency harmonics present in the sharply
truncated sine wave output from a lamp module or wall switch. As a result,
they may heat up and/or burn out. This is true of halogen or fluorescent
lamps that have an integrated transformer. It's true of any device with a
transformer (e.g. some radios and computers) or with a motor (e.g. garage
door opener or electric fan).

A standard APPLIANCE MODULE (X10:AM486) may work for loads that are other
than incandescent lights. Note that when used with a compact fluorescent
bulb, the local control mode in the appliance module often senses a small
current flow and keeps turning on. See Section 5 on defeating local
control. Using an appliance module on a halogen light should work in most
applications, but will not permit remote dimming. If the light has a
built-in dimming control, this can still be used.

There are special modules designed for fluorescent lights and other loads.
Some of these may be in wall switch form but require a neutral power
connection (not all existing wiring designed for a manual on/off switch
have the neutral connection). Others (e.g. LEV:6375) wire directly into
the light fixture and rely on control from some X10 transmitter (e.g.
LEV:6319-4 series). Halogen flood lights work fine in MOTION DETECTOR
(X10:PR511, LEV:6417).

There has been some success reported in using the standard X10
incandescent wall switch for controlling halogen lights that do not have a
transformer in the light fixture. There are many types of halogen bulbs;
mileage may vary. Use at own risk.

Despite the information above and warnings on X10 lamp modules and wall
switches that they be used only for incandescent loads, people persist in
trying to use them for other loads. There are unconfirmed reports that
doing so will cause the module/switch to catch fire (luckily this rarely
happens more than once for a single installation). One should be very sure
that one understands the full implication of going against the
manufacturers' recommendations when directly connecting a device to the
main power supply which will be left unattended in a valuable home.

See also notes on LEV:6291 WALL SWITCH MODULE. This is like a standard
wall switch that will control any load on an off (no dimming). It
incorporates a relay like an appliance module.


Q114. Can I use X10 in a three-way light switching application?

The way lights are normally wired is with a single on/off SPST switch.
When the contacts are closed, the light is on; when open, the light is off:

               *on--------------
              /                |
        -----*                 |
               *(off)        LIGHT
                               |
        ------------------------

In a three-way switching application, a pair of SPDT switches (often at the
top and bottom of stairs) are wired so that the light can be turned on or
off from either switch. (This is sometimes called two-way switching.)
Note that for three-way switching, neither the switches nor the wiring are
the same as for normal on/off switching:


               *----------------*
              /
        -----*                    *---------
                                 /          |
               *----------------*         LIGHT
                                            |
        -------------------------------------

In a situation where a light is already wired for three-way switching, X10
can easily be used. Install the WALL SWITCH 3-WAY KIT (X10:WS4777) -- see
section 2 below. This contains one WALL SWITCH 3-WAY (master) and one WALL
SWITCH 3-WAY REMOTE. Put the master in place of one switch and the remote
in place of the other, wiring carefully as shown in the instructions that
accompany the kit. Note that this is for incandescent lights only and not
for appliances, motors or fluorescent lights.

In fact, this will work where lights are already wired for four- or more-
way switching as well. All you need is one additional WALL SWITCH 3-WAY
REMOTE (available separately) to replace each additional SPDT conventional
switch.

If you are wiring a circuit with the intent of using X10 in a three-way (or
more) light switching application, don't wire it as shown above. A much
simpler and more flexible method is described in Q112.


Q115. What is PLIX?

PLIX stands for Power Line Interface to X-10. It is an 18 pin DIP ASIC
which performs all the timing and decoding necessary to interface a PL-513
transmitter or a TW-523 transmitter/receiver to a microprocessor's TTL I/O
port. In a nutshell, it does all the bit twiddling necessary to send and
receive X-10 commands using a TW-523, simplifying the interface for home
automation software. This allows even interpreted BASIC to send and
receive commands to X-10 devices.

The PLIX chip can send and receive one command at a time. It can receive
and buffer one X-10 command "in the background" (i.e. without any attention
from the host processor) but if a second command comes in before the first
is read the earlier data is overwritten.

The PLIX Evaluation Board kit (PLIX-EKit) is a PLIX chip, printed circuit
board, and all required components. You must assemble it. By hanging a
PLIX-EKit off the parallel printer port on your IBM PC and running the
appropriate software, you can send and receive X-10 commands from your IBM
PC. The PLIX chip also includes an AC Power Failure detect line, which on
the PLIX-EKit is wired to generate an interrupt request to the host PC in
the event of a power failure. As a minimum setup you would probably need a
TW-523 interface and a "straight through" modular telephone cord, plus some
kind of power supply (either a 9V battery or a simple power pack) and a
case if you need it.

The PLIX chip comes with some simple software in BASIC, and there is sample
C code available via anonymous ftp from mrcnext.cso.uiuc.edu:/asre/plix.c
Knowledge of BASIC, Pascal, or C would be more than sufficient to do your
own programming.

The PLIX chip and data sheet is $20 + shipping, and the EKit is $39 +
shipping, both available from the MicroMint.


Q116. Can I use X10 components outside?

>From time to time you may wish to control loads outside your home with X10.
Generally this should be a WALL OUTLET (X10:SR227, LEV:6227) or an
APPLIANCE MODULE (X10:AM466). There are two considerations you must bear
in mind in installing these.

First, the X10 device must be protected from moisture. An appliance module
should not be put outside; you might want to put it in your garage or
garden shed (assuming you have power in these locations) and run an
extension cord to the load out under the door. A more flexible approach
would be to put an X10 wall outlet in an existing outside electrical box.
This must be a weather proof box with tight cover. If you intend to leave
something plugged into it for long periods of time, you will have to find
or make some kind of cover that protects the X10 wall outlet from moisture.

Second, the X10 device should be on a circuit protected a ground fault
circuit interrupter (GFCI, sometimes known as GFI). These are special
outlets that shut down very quickly when they detect some leakage current.
These can put in serial with an appliance module (appliance module plugged
into GFCI outlet), or in parallel (X10 wall outlet wired on load side of
GFCI outlet) as shown below (North American wiring assumed):

                  GFCI
                 outlet
  house current   _____         _____
  ________________|* *|---------|* *|  X10 appliance module (plugged into
  ________________| * |---------| * |   GFCI outlet, protected from
  ________________|   |---------|   |   elements)
            (line)|* *|         -----
                  | * |          ||+-------------
                  -----          |+--------------  load (plugged into
                                 +---------------   appliance module)


  house current   _____           _____
  ________________|* *|___________|* *|
  ________________| * |___________| * |
  ________________|   |___________|   |----------  load (plugged into
            (line)|* *|(load)     |* *|----------   X10 wall outlet)
                  | * |           | * |----------
                  -----           -----
                  GFCI           X10 wall
                 outlet           outlet (in weather proof box)

> See below
> One final warning is about installing the X10 wall switch in an area
> where it will get cold. Apparently the triac in it doesn't work at low
> temperatures. For this reason, you should avoid even putting it in an
> outside wall.

New information (7/95) Many people have had no problem running X10
devices in sub zero temperatures. X10 specifies that the devices
will run from . X10 devices do consume some power at all times and
thus generate some heat. This may affect the working temperature range.

Q117. What are the various combinations of X10 wireless receivers and
transmitters that work together?

WIRELESS TRANSMITTER (X10:RT504, LEV:6313, RS:61-2560) will work with
WIRELESS RECEIVER (X10:RR501, LEV:6314) or WIRELESS RECEIVER (X10:TM751).
To control 16 units, use two X10:RR501 (one set to 1-8, the other set to 9-
16) or one X10:TM751.

The surface mount two, three and four button WIRELESS TRANSMITTERS
(X10:RW684, X10:RW724, X10:RW694 respectively) will work for all codes
with WIRELESS RECEIVER (X10:TM751). When used with WIRELESS RECEIVER
(X10:RR501, LEV:6314), respectively they will only work for units 1-2, 1-3,
or 1-4 if the receiver is set for 1-8; or 9-10, 9-11, or 9-12 if the
receiver is set for 9-16.

The WIRELESS TRANSMITTER (X10:KC674) works for all codes with WIRELESS
RECEIVER (X10:TM751). With the WIRELESS RECEIVER (X10:RR501, LEV:6314), it
will only work for units 1-2 with the receiver set on 1-8.

All the transmitters work with X10 security systems to some degree. Check
before investing. You should not use the WIRELESS RECEIVER (X10:TM751 or
X10:RR501, LEV:6314) if you have an X10 security system (their timing is
slightly different and the signals they put on the power line will
interfere with each other). You should not have two wireless receivers of
any type in close proximity (e.g. in same AC power bar) to each other
(their local oscillators may interfere with each other).

The bottom line is that the WIRELESS RECEIVER (X10:TM751) is much more
flexible than the WIRELESS RECEIVER (X10:RR501, LEV:6314) strictly for
control purposes. If you already have an X10 security system, you should
not need a separate wireless receiver.


Q118. How do I make the motion detector floodlight unit work properly?

MOTION DETECTOR (X10:PR511, LEV:6417) is a useful device that functions as
both X10 receiver and transmitter. It contains a sensor head to detect
motion, an X10 receiver to turn on the attached flood lights, and an X10
transmitter to turn on up to four X10 units when motion is detected or four
other X10 units at dusk and off again at dawn. It also has a shutoff
control with a variable timer to turn the lights (and remote units) off
after motion has stopped. It has a photocell control with variable
sensitivity to determine when dusk and dawn occur.

The most common problems with the motion detector can be solved by reading
the short owner's manual that comes with it. This may seem obvious, but
the answers to the most frequently asked questions are in fact in the
manual.

If the detector does in fact detect motion during daylight hour and you
want it to do so only at night, you need to adjust the DUSK control. Note
that each time you change this, the new value will not become effective
for ten minutes, or one minute if you turn the power off and then on again.

The flood lights on the detector be triggered on either by motion (turns off
after a set time), or by darkness (turns off in the morning). This mode is
set on the THIS UNIT switch, either SENSOR (for motion) or DUSK (for
darkness). Halogen floodlights work fine with this device.

Independent of the setting of the THIS UNIT switch, the detector can turn
on and off up to four remote X10 units when it detects motion. These units
are the four units that follow in numerical sequence from the unit number
of the detector. Thus if the detector is UNIT 1, when motion is detected
(sensitivity controlled by RANGE control), the detector will send X10
signals to turn any or all of (individually selectable) UNITs 2, 3, 4, and
5 ON for the same house code, and turn them OFF again after the selected
time (controlled by TIME DELAY control) has elapsed. As a second example
of the unit codes, if the detector is UNIT 14, then any or all of UNITs 15,
16, 1 and 2 for the same house code can be triggered for motion detection.
To reiterate, the detector can detect motion and trigger up to four
external devices even if the floodlights themselves are set to come on at
dusk and go off at dawn.

Independent of the setting of the THIS UNIT switch, and independent of any
signals sent to remote units upon detection of motion, the detector can
trigger up to four remote units on at dusk and off again at dawn. These
remote units are the four units that are +5, +6, +7 and +8 from the unit
number of the detector. Thus if the detector is UNIT 1, at dusk it will
send X10 signals to turn any or all of (individually selectable) UNITs 6,
7, 8 and 9 ON for the same house code at dusk and OFF again at dawn,
according to the sensitivity set on the DUSK control. As a second example
of the unit codes, if the detector is UNIT 14, then an or all of UNITS 3,
4, 5, and 6 for the same house code can be triggered to be on only during
hours of darkness. To reiterate, the detector can turn on up to four
remote units during darkness even if the floodlights themselves are set to
come on only when the detector detects motion.

The external units triggered by motion cannot be the same as those
triggered by dusk/dawn. Also if the DUSK control is adjusted to the
minimum to detect motion even during the day, the detector will not be
usable for switching lights on and off at sundown and sunup. In this
case, the attached floodlights will come on during the day, either
continuously if THIS UNIT is set to DUSK, or whenever motion is detected if
set to SENSOR.

One typical application would be to have the detector overlooking a back
door or patio. At dusk, the detector would turn on the front exterior
lights and some interior ones to make the empty house look lived-in. When
the detector detects motion in the back yard, it would turn on the attached
floodlights, other interior lights and a recording of vicious dog. These
would go off after the set time. Late in the evening, some sort of X10
timer would turn off the lights that came on at dusk, to simulate the
occupants going to bed.


Q119. How do I control an X10 device from a standard light switch?

The simplest situation is where you have a standard wall switch that
controls a standard wall outlet (sometimes only half of a split outlet).
This is common in newer homes where a switch by the bedroom door controls
an outlet for a light at the bed, or a switch at the living room entrance
controls an outlet for a floor or table lamp.

For the simplest case, you'll need an AC adaptor that puts out a DC or AC
voltage in the range 6-18 VDC, and an POWERFLASH INTERFACE (X10:PF284,
RS:61-2687). Plug AC adaptor into controlled wall outlet. Plug the
POWERFLASH INTERFACE into an adjacent wall outlet that is continuously on
(may be the other half of the split outlet). Connect the output of the AC
adaptor to the input of the POWERFLASH INTERFACE, select input mode 3 and
select which unit you wish to control with the dial on the POWERFLASH
INTERFACE.

When you turn on the wall switch, a voltage will be produced by the AC
adaptor and trigger the POWERFLASH INTERFACE to send the X10 ON command to
the selected unit. When you turn off the wall switch, this will cut
current to the AC adaptor and the POWERFLASH INTERFACE will send the OFF
command to the selected unit.

The not-so-simple situation is where your wall switch controls a light
fixture. In this case, you would have to hard wire the above components
into place, or install a split power outlet half controlled by the switch
and plug them in.


Q120. How do I control my garage door with X10?

Stanley makes a Light Maker garage door opener that receives and sends
X10-like signals which don't seem to be too compatible with standard
X10. There have been reports of a jammed door flooding the power line
with these signals and so jamming the X10 channel.

A standard electric garage door opener is actuated by a simple contact
closure. This can be triggered by an X10 event using the UNIVERSAL LOW
VOLTAGE MODULE (X10:UM506, LEV:6337, RS:61-2688) in momentary mode
connected to the existing garage door control contacts, possibly in
parallel with the existing manual switch. When the selected X10 command is
received (unit ON) from whatever controller, either wired or wireless, the
contacts are closed and the door opens or closes.

A more sophisticated control system could be set up using two UNIVERSAL LOW
VOLTAGE MODULEs and some means of detecting whether the door is already
open or closed. This could be simple magnetic reed switches on the door,
or signals from the motor controller (it knows when to stop opening or
closing the door). The idea is to accept only signals from one UNIVERSAL LOW
VOLTAGE MODULE when the door is open, and from the other only when the door
is closed. This would mean a different command (e.g. "1 ON") to open the
door, and to close the door (e.g. "2 ON").

A further "improvement" would be to connect an AC adaptor so it is powered
by the light socket or light circuit on the garage door opener, and
connect it to a POWERFLASH INTERFACE (X10:PF284, RS:61-2687). This would
have the lights in the garage (or anywhere else in the house) on when the
door is open. See details in Q119.

Using a wireless transmitter such as WIRELESS TRANSMITTER (X10:RT504,
LEV:6313, RS:61-2560) to control the garage door might seem like a good
idea. However, it's not very secure. Anyone with a similar transmitter
and the right unit and house codes (256 possible combinations) could open
your door. Many conventional garage door openers have a thousand or more
different codes from which you can choose.


Q121. How do I improve the accuracy of my CP290 Home Control Interface?

The CP290 Home Control Interface, for reasons unknown to mortal man,
does not take its clock timing from the power line to which it is always
connected except during power outages. It uses an internal crystal
oscillator which is generally not particularly accurate. Errors of a
several minutes per week have been reported. This is particularly
annoying for a device that is supposed to perform time control of
devices.

One approach is to replace the crystal with a higher tolerance one. The
procedure to do this is in Q511.

For those not inclined to brandish a soldering iron, the trick is to update
the CP290 clock regularly from a more accurate source. This could be done
manually using a wristwatch; most CP290 software provides a means to set
the internal clock manually. A bit better method would be automatically
from the computer to which the CP290 is connected; the internal computer
clock is usually more accurate (or more easily controlled) than the clock
in the CP290.

The software details for setting the CP290 clock are in Section 4 of this
FAQ. A simple utility could be written to synchronize the clock of the
CP290 with the clock of the computer every time the computer was turned on
(e.g. include in computer startup command file). Note for best accuracy
and consistency, the CP290 clock should be updated at the minute plus zero
seconds (i.e. exactly on the minute).

Q122. How do I make an X10 light brighten up from zero intensity?

Many people come up with the "requirement" to have an X10 light start from
zero intensity (off) and ramp up to some level of brightness, to simulate
sunrise, to avoid waking them up when they go to the bathroom etc.

The standard X10 incandescent dimmers (e.g. DIMMING FIXTURE MODULE
LEV:6376 or LAMP MODULE X10:LM465) cannot go to a absolute level of
brightness other than off or on. If the device is off and it receives
DIM commands, it will come on to full brightness and then start to dim
(i.e. relative rather than absolute) until it receives no more DIM
commands. If it dims right down to the point where the light it controls
is actually off, then it can be brightened up again manually to some
intermediate level. However if the device gets an OFF command (from an
ALL OFF perhaps) in the meantime, there is no way to set it to anything
less than full brightness without it first coming on at full brightness
and then dimming down.

Powerline Control Systems (see Q105) manufactures a line of X10 devices
that are much more flexible than the traditional (and inexpensive) ones
that are widely used. One feature of their incandescent control devices
is that they can start at zero brightness and go to any of 200 discrete
levels of brightness. They can also go directly to a pre-set brightness
level. Traditional X10 controllers may not be able to control these
settings, however.


Q123. What components are available for me to build my own X10 modules?

1. PIC Home Automation Library written by Ed Cheung. Note this is PIC
assembly code! Send email to Ed at [e-mail] if you
would like a copy. Also available at the FAQ ftp site, see
ftp://ftp.scruz.net/users/cichlid/public/

  "In my effort to move my Home Automation system to a distributed
  processing system, I have invested some time into programming the
  line of microprocessors from Microchip (the PICs).  I have decided to
  see if there is any interest in the library, and release it as shareware.

  "The library that I have created is interrupt driven and has the following
  modules: X-10 (using a TW523), IR (Sony SIRCS), LCD display, Analog to
  Digital (I use the P16C71), RS232, RS422, and RS485.  The interrupt
  driven nature allows the main program to set variables and initiate
  transmission.  The background processes will send the data out at the
  right time and rate.  In this manner, each chip can also receive several
  types of serial data at once (receive RS232 byte and X-10 at the same time).

  "I intend to have my computational nodes be compatible (but not identical)
  to HCSII's protocol.  AFAIK that is 9600 baud RS485 in a master-slave
  configuration (nodes speak only when they are spoken to).


2. BASIC Stamp II

  <insert blurb here>

  http://www.parallaxinc.com
  ftp://ftp.parallaxinc.com/pub


Q124: What patents cover the X10 system?

These are US patent numbers.

    4 - 189 - 713
    4 - 200 - 862
    4 - 628 - 440
    4 - 638 - 299
    5 - 005 - 187

More patent information from David Buckley [e-mail]:

X-10 Patents - The story so far...

There are four patents directly covering X-10, each of which appears
in a number of forms for the varying requirements of the given
patent authority.  All patents are assigned to Pico Electronics
Limited, of Scotland, in the United Kingdom.


The First and Main X-10 Patent:

This covers most of the essential features of X-10 as we know it.
It's all there, 120Khz pulses, timing, sending commands twice (more
accurately, 'at least once'), including little things like dimming
commands, and ultrasonic remote control.  This latter feature is
probably because Pico Electronics also have a patent on ultrasonic
remotes, using PWM technology.

David Chester Campbell, David Richard Thompson.
UK: Filed as 19428/77, Abandoned
UK: 1592971, filed 7Jan77, pub 15Jul81
US: 4,200,862, filed 28Dec77, pub 29Apr80
De: 2800472


The Second Patent:

This patent has a sketch of a US style (decora?) wall plate with 4
rocker 'buttons' on it.  It knows how to handle two or more buttons
pressed together.

The concept of 'collision detection' is added, i.e., it listens to
the mains to ensure it doesn't transmit when someone else is already
doing so.

Also, this patent covers 'multiple unit addressing' from one button
press.

Finally, the concept of transmitting the carrier bursts over the
full half cycle is covered, as an aid to more reliable operation
particularly in multi-phase scenarios.

There is also a disclaimer to a number of the claims of the US
version of patent filed (gazette 15May88), but despite intensive
searching, I couldn't find it!

US: 4,628,440, Filed 12Nov85, pub 9Dec86
UK: Filed as 81/32173, withdrawn, replaced by EP.
EP: 0078,171, Filed 25Oct82, Pub 7Jan88


The Repeater Patent:

This covers regenerating X-10 commands across phases and separate
electrical systems.  It also amplifies (ugh!) on the earlier
statement that commands are sent twice, rather than 'at least once'.

Author: David C Campbell
US: 4,638,299, Filed 28Mar83, Pub 20Jan87
UK: Filed as 82/10198, withdrawn.
EP: 0,091,290, Filed 31Mar83, Pub 19Nov87

The Better Receiver Patent:

Most early X-10 designed used an analogue method of 120Khz tone
detection.  This patent suggests using digital techniques,
implemented in software, to extract the tone.  This stuff will be
familiar to any DSP gurus, and the maths is well above me.  Claim is
for improved performance in poor signal and high noise environments.

US: 5,005,187, filed: 23Mar89, Pub 24Apr91.

Other things bumped into during research:

UK 1535834 and 1535835, US 3,911,415:  All from Westinghouse.  X-10
differentiates itself from these patents, which are all to do with
reading electricity meters remotely etc.  Filed 26Jan76, pub
13Dec78.

US 4,418,333 - This is the first useful input from WWW searches,
covers the concept of the remembered light level in a remote control
system.  Donald J Yusko, assigned to Pittway Corp, pub 29Nov83.

US 43,777,754 - Also from a web search, and despite the number
looking wrong, it's what it said.  Covers the quick "off on off"
flick to change an appliance from the off state to on.  Another one
from Pico Electronics.  Filed 26Feb81, pub 22Mar83.

Note: I didn't see the words 'Powerhouse' or 'X10' during any of the
reviewing.


Q125. What radio frequencies do X10 componants use?

Control remotes and security use 310 Mhz. Powermid uses 410 Mhz.


Q126. Where did X10 come from? (by Neil Duffy)

Pico electronics was (and is?) a small design house in Glenrothes, Fife,
Scotland. Its founders were originally employed by General Instruments
in Glenrothes but broke away to form Pico Electronics. Their first
designs were among the first of the electronic calculator chips. Chips
designed by Pico and manufactured by GI appeared in the calculators of
many manufacturers.

A second venture following on from the calculators was a track selecting
record deck in which an led/ photodiode pair was used to detect the
spaces between tracks on an LP. The usere could play the tracks in any
order, rather like the facilities that CD players provide today. This
project was given the internal code name X9 but eventually became the
ADC Accutrack. The Accutrack originally had an ultrasonic remote control
which transmitted bursts of 40khz. It repeated the code in blocks of two
words, one of the words if I remember rightly being the inverse of the
other. The receiver compared the two before accepting the command.

The next project was given the internal code name of X10 following on
from X9 and was never renamed. The original X10 units used a similar
design to the ultrasonic remote control of the Accutrack.


<FAQ SECTION 2>

SECTION 2:  INFORMATION ON X10 COMPONENTS
==========================================

Manufacturers' numbers shown below are coded as follows:

 X10:  X-10 Powerhouse
 LEV:  Leviton Decora Electronic Controls
 RS:   Radio Shack Plug 'N Power

Prices are included (for the X10 model unless otherwise noted) from
Worthington as of 7/95 rounded to the nearest dollar to give you a
general idea. These prices are less than retail. These prices will not
be updated regularly so get a catalog from one of the suppliers listed
elsewhere (they're free).

==========================================================
Intelligent Controllers, Computer and Telephone Interfaces
==========================================================

COMPUTER INTERFACE (X10:PL513). Send only computer interface module.

COMPUTER INTERFACE (X10:TW523). $18 Semi-intelligent computer interface
to the power line, recommended for developers only. It plugs into an
outlet and allows a computer or microcontroller to talk and listen
directly to the X10 command codes on the AC line. It's roughly the size
of a lamp module. See details in Q109.

X10 COPROCESSOR (MARRICK) $115 (with cables, TW523, power supply) $49
(kit, board and parts, no TW523 etc) Intelligent computer interface. Two
way X-10 communication, serial (RS-232) interface, 4" x 5" PCB has
prototype area for expansion. No polling required, sends to computer
serial port when X10 activity is detected.  LED indicators (receive
transmit error busy).  Enhanced X10 command functionality: broadcast
messages such as ALL LIGHTS ON ALL HOUSE CODES and DIM TO LEVEL. Keeps
time since last power failure.  Commands are all in standard ASCII.

MINI-TIMER (X10:MT522, RS:61-2670). $19 Battery backed up clock,
Functions: on or off at exact time or approximate time twice each day
for 4 modules.  Manual control: off on, all lights on for 8 modules.

CLOCK RADIO TIMER (RS:61-2671). $40 AM/FM clock radio, battery back up.
Functions: on or off at exact time or approximate time twice each day
for 4 modules.  Manual control: off on, all lights on for 8 modules.
Wake to FM, AM or beep alarm.

TELEPHONE INTERFACE (X10:TR551, RS:61-2692). $51 Answers phone, controls
10 modules from commands on remote DTMF phone

TELEPHONE TRANSPONDER (LEV:6325). $110 Answers phone, controls all 256
possible units for commands on remote DTMF phone, three digit access
code, confirms all commands with synthesized voice

HOME CONTROL INTERFACE (X10:CP290, RS:61-2617). $42 Battery backed up
clock, seven day cycle, 128 events set by computer connected to RS-232
interface, any house code, any unit codes. Manual control:  units 1-8
for the base house code set on the unit, on or off. Comes with software
for any one of (not all) PC, Mac, Apple ][ or Commodore 64/128 and
appropriate serial cable. Computer can be turned off or disconnected
once the interface has been programmed and it continues on by itself.

DELUXE WALL MOUNTED PROGRAMMER (LEV:6311). 7-day scheduling for up to 63
program sequences, any 16 unit codes ON or OFF, has manual control feature
that doesn't affect the preprogrammed sequences, battery backup.

BASIC WALL MOUNTED PROGRAMMER (LEV:6312). Controls up to 4 unit codes, with
a maximum of 2 ON and 2 OFF codes for each unit, allows for SECURITY mode
like the two RS timers (ON or OFF happens during a 15-minute window).  Has
manual control buttons, battery backup.

===========================================
Dumb Controllers, Transmitters and Switches
===========================================

MINI-CONTROLLER (X10:MC460, RS:61-2677). $8 Controls either units 1-4
or 5-8 (selectable) for any single house code. Functions: on, off, dim,
all lights on, all off.  Connects to standard wall outlet.

MAXI-CONTROLLER (X10:SC503, LEV:6320, RS:61-2690). $16 Controls units
1-16 for any single house code. Functions: on, off, dim, all lights on,
all off.  Connects to standard wall outlet.

SUNDOWNER (X10:SD533). $13 Same as MINI-CONTROLLER. Also will turn four
units on at sundown and off at sunup as determined by internal
photocell.  Connects to standard wall outlet.

PHOTOCELL WALL MOUNT CONTROLLER (LEV:6308).  Mounts in a round electric
box, sends ON commands to up to 4 unit codes at dusk or dark, sends OFF
commands at dawn or after a preset number of hours.

WALL MOUNTED CONTROLLER (LEV:6319-4). $46 Turns any four consecutive
units on or off. Push button switches. Wired into rectangular wall box.

WALL MOUNTED CONTROLLER (LEV:6319-4D). $46 Turns any three consecutive
units on, off or dim. Push button switches. Wired into rectangular wall
box.

WALL MOUNTED CONTROLLER (LEV:6319-4A). $46 Turns any three consecutive
units on or off. Also provides ALL ON and ALL OFF commands. Push button
switches. Wired into rectangular wall box.

WALL MOUNTED CONTROLLER (LEV:6319-2). $46 Turns any two consecutive
units on or off. Push button switches. Wired into rectangular wall box.

WALL MOUNTED CONTROLLER (LEV:6319-2D). $46 Turns any unit on, off or
dim. Push button switches. Wired into rectangular wall box.

WALL MOUNTED CONTROLLER (LEV:6319-2D). $46 Turns any unit on or off.
Push button switches. Wired into rectangular wall box.

WALL MOUNTED CONTROLLER (LEV:6319-1A). $46 Provides ALL ON and ALL OFF
commands. Push button switches. Wired into rectangular wall box.

UNI-BASE WALL MOUNTED CONTROLLER (LEV:6400).  Replacement for the older
6319 line of controllers, accepts the 1, 2 or 4 button face plates with LED
status lights.  Neither the controller nor the face plates are compatible
the the 6319-series controllers!  The switches have pre-printed labels with
plastic covers to protect the labels, or you can label them yourself.
Faces below are $10 each.

ONE BUTTON ON/OFF FACE (LEV:6400-1). Sends ON or OFF commands to one unit.

ONE BUTTON ALL ON/OFF FACE (LEV:6400-1A). Sends ALL LIGHTS ON and OFF.

TWO BUTTON ON/OFF FACE (LEV:6400-2). Sends ON or OFF to two units.

TWO BUTTON DIMMING FACE (LEV:6400-2). Sends ON, OFF, DIM, BRIGHT to one unit.

FOUR BUTTON ON/OFF FACE (LEV:6400-4). Sends ON or OFF commands to four units.

FOUR BUTTON ON/OFF ALL ON/OFF FACE (LEV:6400-4A). Sends ON or OFF commands
to three units, bottom button sends ALL LIGHTS ON or ALL LIGHTS OFF.

FOUR BUTTON DIMMING FACE (LEV:6400-4D). Sends ON or OFF commands to three
units, bottom button sends DIM or BRIGHT commands to the same 3 units.

WALL SWITCH (X10:WS467, RS:61-2683). $10 Replaces standard wall switch,
wired into rectangular wall box. Manual toggle of on or off. May be
locked in off position.  Dims and brightens from remote controllers.
500W resistive max, 400 watts each in dual-gang box, 300 watts each in
triple-gang box.

WALL SWITCH 3-WAY (X10:WS477). $14 Same as standard WALL SWITCH, but for
use with three way switch (on/off at two or more locations).

WALL SWITCH 3-WAY REMOTE (X10:CS277). $6 Used with WALL SWITCH 3-WAY.
For on/off at two or more locations, one must be WALL SWITCH 3-WAY,
others must be WALL SWITCH 3-WAY REMOTE. One of these is included with
WS4777, but they are also available separately.

WALL SWITCH 3-WAY KIT (X10:WS4777, RS:61-2686). $14 Kit of WALL SWITCH
3-WAY (X10:WS477) and WALL SWITCH 3-WAY REMOTE. (not sure if this is
different from WS477)

WALL SWITCH MODULE (LEV:6291). $45 This is a cross between a wall switch
and an appliance module. It has an internal relay and a manual switch to
turn on and off loads other than incandescent lamps, 20A 120V maximum.

240V DOUBLE POLE WALL SWITCH MODULE (LEV:6371).  Intended for pool
pumps, spa motors and heaters, and other large loads (2HP max).
Responds to ALL LIGHTS ON/OFF and ON/OFF commands.  240V 20A 60Hz.

3-WAY WALL SWITCH MODULE (LEV:6293).  This is a cross between a wall
switch and an appliance module. It has an internal relay and a manual
switch to turn on and off loads other than incandescent lamps, 20A 120V
maximum.  Can be wired in a 3-way or 4-way configuration (with additional
slave modules LEV:6294)

LOW VOLTAGE DIMMING SWITCH (LEV:6381).  Same as standard WALL SWITCH,
but is rated to control ceiling fans, motors and magnetic transformers,
in addition to incandescent lights.  500W or 500VA maximum.  Has a built-
in RFI filter.

LOW VOLTAGE 3-WAY DIMMING SWITCH (LEV:6383).  Same as LEV:6381 switch
but is the 3-way version, using LEV:6294 for the slave units.  Rated to
control ceiling fans, motors and magnetic transformers, in addition to
incandescent lights.  500W or 500VA maximum.  Has a built-in RFI filter.

=========
Receivers
=========

APPLIANCE MODULE (X10:AM486, RS:61-2681). $10 Responds to any house code,
any single unit. Turns load (15A, motors up to 1/3 HP, 500W for lights)
either on or off. Two pin polarized.

APPLIANCE MODULE (X10:AM466, RS:61-2684). $11 Same as APPLIANCE MODULE
(X10:AM486), but three pin grounded.

SCREW IN LAMP MODULE (X10:SL575, RS:61-2566). $12 Same function as lamp
module (X10:465) but screws in between existing light fixture and bulb.
Controls up to 150 watts.

FIXTURE RELAY MODULE (LEV:6375). $50 This module does not plug into an
outlet, but must be wired into the circuit. It switches a relay that
handles 5A for incandescent or fluorescent lights. Responds to ON, OFF,
ALL LIGHTS ON, and ALL OFF commands.

DIMMING FIXTURE MODULE (LEV:6376). $44 Similar to FIXTURE RELAY MODULE
(LEV:6375) but has no relay and will dim up to 300W incandescent lights.
Responds to DIM and BRIGHTEN commands as well as ON, OFF, ALL LIGHTS ON,
and ALL OFF commands.

2400W DIMMING MODULE (LEV:6290).  Similar to DIMMING FIXTURE MODULE
but controls up to 2400 watts (resistive).  Doesn't say it's capable of
working with inductive loads like motors or fans.  Responds to DIM and
BRIGHTEN commands as well as ON, OFF, ALL LIGHTS ON and ALL OFF commands.

LAMP MODULE (X10:LM465, RS:61-2682). $10 Responds to any house code, any
single unit.  Turns incandescent light (300W max) on, off, or dim.
Reportedly melts if connected to anything else.

WALL OUTLET (X10:SR227, LEV:6227, RS:61-2685). $14 Similar to APPLIANCE
MODULE 15 A, 800W) but replaces standard wall outlet, wired into
rectangular wall box. One outlet is X10 controlled; other is always on.

WALL OUTLET DUPLEX (LEV:6280). Similar to WALL OUTLET, but both outlets
are controlled as a single unit. Does not respond to ALL LIGHTS OFF.

SINGLE WALL OUTLET (LEV:6297). Similar to WALL OUTLET, but only has one
controlled 15A outlet.  Does not do local control sensing, and will not
respond to ALLL LIGHTS ON command.

SINGLE WALL OUTLET (LEV:6298). Similar to WALL OUTLET, but only has one
controlled 20A outlet.  Does not do local control sensing, and will not
respond to ALLL LIGHTS ON command.

SINGLE WALL OUTLET (LEV:6296). Similar to LEV:6298 (single 20A outlet)
but it also responds to local control sensing.

WALL OUTLET 220V, 15A (X10:HD243, RS:61-2668). $16 Controls 220V
appliances (e.g. water heater) up to 15A, mono phase or split two phase,
standard North American wiring.

WALL OUTLET 220V, 20A (X10:HD245, RS:61-2669). $16 Same as WALL OUTLET
220V 15A but for up to 20A.

========
Wireless
========

WIRELESS RECEIVER (X10:RR501, LEV:6314, RS:61-2608). $30 (LEV) Receives
X10 commands by radio signals from WIRELESS TRANSMITTER (X10:RT504,
LEV:6313) and retransmits them into house wiring for any eight units.
Also has integrated appliance module.

WIRELESS RECEIVER (X10:TM751). $13 Receives X10 commands by radio
signals from WIRELESS TRANSMITTER and retransmits them into house wiring
for any two units. Also has integrated appliance module.

SMART RF REPEATER (X10:SR731). $64 Receives commands by radio signals
from any WIRELESS TRANSMITTER (X-10 or SECURITY) and retransmits them
to any WIRELESS RECEIVER for any 16 units.  Does not work with POWERMID.

WIRELESS TRANSMITTER (X10:RT504, LEV:6313, RS:61-2560). $13 Controls
units 1-8 or 9-16 for any house code by sending radio signals to a
WIRELESS RECEIVER (X10:RR501, LEV:6314).

WIRELESS TRANSMITTER (X10:KC674, RS:61-2565). $12 Turns any two units on
or off by sending radio signals to WIRELESS RECEIVER (X10:TM571 or
RR501), keychain size.

WIRELESS TRANSMITTER (X10:RW684, RS:61-2562). $12 Turns any two units on
or off by sending radio signals to WIRELESS RECEIVER (X10:TM571 or
RR501), surface mount.

WIRELESS TRANSMITTER (X10:RW694, RS:61-2664). $12 Turns any four units
on or off by sending radio signals to WIRELESS RECEIVER (X10:TM571 or
RR501), surface mount.

WIRELESS TRANSMITTER (X10:RW724, RS:61-2563). $12 Turns any three units
on, off or dim by sending radio signals to WIRELESS RECEIVER (X10:TM571
or RR501), surface mount.

================
Security Systems
================

WIRELESS SECURITY RECEIVER CONSOLE (X10:BR521, RS:61-2611). $110
Receives security commands from wireless transmitters (X10:DW534,
RS:61-2612, X10:SP544, X10:HT544, RS:61-2611, X10:SH624, X10:KF574) to
arm, disarm and trip it's 85dB siren, and flashes ALL LIGHTS ON and ALL
LIGHTS OFF commands to the house wiring when tripped.  It also
retransmits commands from other wireless X-10 transmitters to the house
wiring for any 16 units.  Supports 8 security unit codes, has a battery
backup, wall mount.

WIRELESS SECURITY RECEIVER & AUTODIALER (X10:PS561, RS:61-2610). $133
Receives security commands from wireless transmitters (X10:DW534,
RS:61-2612, X10:SP544, X10:HT544, RS:61-2611, X10:SH624, X10:KF574) to
arm, disarm and trip it's 95dB siren, flashes ALL LIGHTS ON and ALL
LIGHTS OFF commands to the house wiring and calls up to 4 telephones
with a 15 second message when tripped. It also retransmits commands from
other wireless X-10 transmitters to the house wiring for any 16 units.
Supports 8 security unit codes, has a battery backup.

WIRELESS TRANSMITTER (X10:SH624). $26 Arms and disarms alarm consoles and
turns any four units on, off or dim by sending radio signals to SECURITY
RECEIVER (X10:BR521, RS:61-2611, X10:PS561), surface mount.

WIRELESS TRANSMITTER (X10:HT544, RS:61-2611T). $26 Arms and disarms alarm
consoles and turns any single unit on or off by sending radio signals to
SECURITY RECEIVER (X10:BR521, RS:61-2611, X10:PS561), handheld.

WIRELESS TRANSMITTER (X10:KF574). $26 Arms and disarms alarm consoles and
turns any single unit on or off by sending radio signals to SECURITY
RECEIVER (X10:BR521, RS:61-2611, X10:PS561), keychain size.

WIRELESS DOOR/WINDOW TRANSMITTER (X10:DW534, RS:61-2612). $21 Monitors the
included magnetic reed switches and sends alarm trip signal to SECURITY
RECEIVER (X10:BR521, RS:61-2611, X10:PS561), surface mount.

PIR MOTION DETECTOR (X10:SP544A) $60 Passive InfraRed motion detector,
any movement sends an alarm trip signal to SECURITY RECEIVER (X10:BR521,
RS:61-2611, X10:PS561), surface mount.

===================
Personal Assistance
===================

WIRELESS ASSISTANCE RECEIVER AND AUTODIALER CONSOLE (X10:PA581). $133
Receives commands from wireless pendant transmitters (X10:HP564,
X10:PT594) to sound it's 95dB siren, flashes ALL LIGHTS ON and ALL LIGHTS
OFF commands to the house wiring and call up to 4 telephones with a 15
second message when tripped.  Supports up to 8 pendants, and can
retransmit commands from any WIRELESS TRANSMITTERS over the house wiring.

WATER-RESISTANT CALL PENDANT (X10:HP564). $26 Wireless transmitter to
trip the ASSISTANCE CONSOLE (X10:PA581).

CALL PENDANT WITH LIGHT CONTROL (X10:PT594). $26 Wireless transmitter to
trip the ASSISTANCE CONSOLE (X10:PA581) any units ON or OFF if they have
the same housecode and unit code as the ASSISTANCE CONSOLE.

================
Special Function
================

MOTION DETECTOR (X10:PR511, LEV:6417, RS:61-2604). $38 At sundown, sends
ON command for any up to four consecutive units and sends OFF again at
sunup. Also only when dark, sends ON command to up to four other
consecutive units when motion detected. Two floodlight sockets turned
on/off for either sundown/sunup or when motion detected (selectable).
Adjustable sensitivity for sunup/sundown and on/off time delay for
motion. For outside use. Must be wired into round electrical box.

POWER HORN (X10:PH508, RS:61-2613). $30 This is a very loud (100dB)
piezo electric device used as the audible indicator to scare away or
deafen intruders. It sounds in response to X10 signals, usually
generated by other components in a complete X10 alarm system.

THERMOSTAT CONTROLLER (X10:TH2807). $13 Attaches to appliance module.
Small heater underneath any thermostat fools it into thinking house is
warm and furnace need not be turned on. Good for use with automatic
timer (e.g. MINI-TIMER or HOME CONTROL INTERFACE).

DRY CONTACT TRANSMITTER (LEV:6315). $98 Transmits X10 ON and OFF signals
to four consecutive units in response to make or break connections of
dry contact sensors (e.g. photocells, external alarm systems). Wired
into rectangular wall box.

MOMENTARY DRY CONTACT TRANSMITTER (LEV:6316). $98 Similar to DRY
CONTRACT TRANSMITTER (LEV:6315) but triggers on momentary changes in the
external dry contact sensors.

UNIVERSAL LOW VOLTAGE MODULE (X10:UM506, LEV:6337, RS:61-2688). $16
Selectable for any house code, any unit code. Closes external circuit
(selectable continuous or momentary) in response to X10 command. Has
integrated REMOTE CHIME function. Plugs into standard wall outlet. For
controlling sprinklers, curtain closers whose control signals are not
120V but rely on simple switch closing.

POWERFLASH INTERFACE (X10:PF284, RS:61-2687). $18 In response to 6-18 VAC
or VDC does one of the following three things (selectable): turns all
lights on then selected unit on, and then selected unit off when voltage
is removed [mode1]; repeats all lights on, all units off as long as
voltage is applied (effect is to flash all lights), ends with all lights
on [mode2]; transmits selected unit code on when voltage is applied, and
selected unit off when voltage is removed [mode 3]

REMOTE CHIME (X10:SC546). $16 Chimes when turned on. Selectable for any
house code, any unit code. Could be used with MOTION DETECTOR to warn
when someone is approaching.

================================
Amplifiers, Couplers and Bridges
================================

If the installation of one of these devices make your system perform
worse its possible that there is a noise source inside your house and
now the noise is being amplified/coupled to the other phase.

SYSTEM AMPLIFIER (LEV:6201). $262 Boosts signals on one phase and
retransmits them on the other in North American 120/240V wiring system.
Installed on its own 15A breaker at main electrical panel. Often
required for large buildings over 5000 square feet (465 square meters).

SIGNAL BRIDGE (LEV:6299). $33 Couples signals from one phase to other in
North American 120/240V wiring system. Installed on its own 15A breaker
in rectangular wall box. Often required in medium sized buildings over
2000 square feet (185 square meters), or smaller where commands do not
pass reliably.

NOISE BLOCK (LEV:6282). Installed between incoming power line and
main panel to keep extraneous electronic noise and signals from entering
or leaving X10 network. Useful in apartments or attached homes sharing
same transformer with others. 100A per phase.

NOISE FILTER (LEV:6288). $21 Looks like appliance module. Installed
between power outlet and power cord of particularly noisy appliance that
is interfering with X10 signals.

IN-LINE NOISE FILTER (LEV:6289).  Meant to be installed with pigtail
wires inside devices that interfere with X-10 signals, such as fluorescent
lights or dimmers.  Can be wired phase to neutral or phase to phase.

WHOLE HOUSE BLOCKING COUPLER (ACT CP303). $75 Couples signals across
phases and blocks outside X10 signals. See Section 2.1.


SECTION 2.1: EXPANDED INFORMATION ON X10 COMPONENTS

WHOLE HOUSE BLOCKING COUPLER (ACT CP303)

The following is an edited version of an article posted by Edward Cheung
(7/95).

  One week ago I posted an article asking for info on ACT's blocking
  coupler. Since then I have had one installed in my house, and I am
  happy to report that it works as claimed. As promised, I am posting a
  report on my findings in the hope that it may benefit others.

  A few months ago, I started receiving X-10 commands from my neighbor
  down the street. Since our homes are wired for 200Amp service, I had
  previously assumed that we didn't share transformer secondaries. This
  assumption was either incorrect, or commands were somehow bridging the
  secondaries.  Note that he does _not_ use RF components.

  An ad from Worthington industries in an issue of Electronic House
  proclaimed the arrival of a new device from ACT that promises to
  isolate your house from the rest of the street for $75.00. In
  addition, the unit also functions as a phase coupler. As I will
  explain below, this latter function is very important for proper
  operation of the blocker.  After ordering one unit and setting up a
  bench test circuit at home, I was able to use my scope to measure that
  the device indeed attenuates X-10 signals by a factor of four to five.
  Tech lit from their company president Rick Scholl states that if the
  amplitude of the offending X-10 command exceeds 100mV, two such
  filters will be needed (one at each house's breaker panel) to block
  all signals.

  The device's principle of operation is quite clever. In a conventional
  design, you would have to insert an inductor of sufficient value and
  current rating in series with each incoming power phase. The size of
  such a device can be enormous. Instead of that approach, the ACT
  blocker is a toroidal transformer. The installer passes the neutral
  conductor to the house's breaker panel thru a hole in the noise
  blocker and connects the incoming neutral and power phase connections
  to screw terminals on the device.  Note that the device is _not_ in
  series with the house, thus mega size conductors are not needed.  The
  actual operation of the circuit is not 100% clear to me, but it
  functions roughly as follows: when an offensive signal is detected by
  the module, it somehow figures out its source (either from in or
  outside the house), and then magnetically induces a voltage of the
  proper polarity on the segment of the neutral cable that is inside the
  toroid's hole. The effect is that the signal will be canceled out.
  For example, if there appears 10mV of signal on phase A, it will be
  automatically be coupled also to phase B.  ACT's blocker then induces
  roughly 10mV of signal onto the neutral, and the effect is that the
  house 'sees' no signal, since there exist an equal amount of 'noise'
  on all three connections.

  The device has been installed in my home for a few days, and since
  then there has been a complete cessation of outside commands. I
  suppose that I would be willing to accept one or two commands from the
  other homes per week, and so far, we are below that threshold. X-10
  performance inside the home has been unchanged.

  The device is small. It will fit inside a regular coffee mug. In my
  case, this allowed an inexpensive installation--right into the breaker
  panel. If it were much larger, it would require a much costlier and
  lengthier installation. The electrician I hired needed one hour, a
  total cost of $80. In principle, there is no reason that the frequency
  response of the device be limited to the X-10 carrier. Perhaps the
  unit can / does function as an active high frequency fire wall for the
  house.  In this case, it can add a side benefit of reducing line noise
  in general. I wonder then if this device can also be useful with the
  next generation of powerline carrier control such as CEBUS and
  Echelon.  Leviton is also building a whole house block, and has been
  advertised for several months in Home Control Concept's flyer. As of
  Feb '95, this unit will not be available till late Summer '95, and is
  rumored to cost a few hundred dollars. I do not know how Leviton's
  device works, but from the drawings that I have, I do not see any thru
  holes. In addition, the Leviton device handles only two phases (up to
  100Amps each), while ACT's can handle up to three (up to 200Amps
  each). I wonder if Leviton's device is just two big inductors. If the
  amount of attenuation of intruding signals is not sufficient, it would
  appear to be possible to install capacitors across the power lines on
  the meter side of the blocker to suppress these signals.  I say this
  hesitantly as there are extraneous issues associated with doing this,
  so tread carefully. This device is very new. The serial number of mine
  is #109. The part number is CP303, and it is UL listed.

<FAQ SECTION 3>

SECTION 3:  DETAILS ON X10 PROTOCOL
====================================

Note: This section applies to 60 Hz North American wiring. Relevance of
this to European wiring is not known.

Each ONE bit in a legitimate X10 transmission is a 1 millisecond (mS) pulse
code modulated burst of 120KHz on the AC line, and each ZERO is the absence
of that burst. The exact length of the burst may not be too critical in
most applications. The burst is sent three times for each bit, once at
each AC zero-crossing (accounting for zero-crossing in 3-phase). That
means once each 2.778 mS. The next bit is sent on the following zero-
crossing. This is done to get the quietest time on the AC line for the
receiver, whatever phase of the AC it's on. The zero crossing gives the
best signal-to-noise ratio for data transmission because everything should
be shut down then (i.e. the voltage is low).

              . . .                                                      .
           .         .                                                .
        .               .                                          .
     .                      .                                   .
  ._____________________________._____________________________.___________
  ^         ^         ^         ^ .     ^         ^       . ^         ^
  1         1         1         2    .  2         2    .    3        etc.
                                        .           .
                                            . . .


In addition, each bit is sent both true and complemented, and each code
sequence is sent twice. That's a lot of bit redundancy, and just barely
enough to make it past the noise on the line, depending on actual
conditions.

A single normal command takes eleven cycles of the AC line to finish. All
legal commands must first start with the header 1110, a unique code as
described below. The header bits take two cycles at one bit per half
cycle. The next four cycles are the four-bit House Code, but it takes
eight bits total because each bit is sent true then complemented. This is
similar to biphase encoding, as the bit value changes state half-way
through the transmission, and improves transmission reliability. The last
five AC cycles are the Unit / Function Code, a five bit code that takes ten
bits (again, true then complemented). For any codes except the DIM, BRIGHT
and the data following the EXTENDED DATA function, there's a mandatory
three cycle pause before sending another command DIM and BRIGHT don't
necessarily need a pause, and the data after the EXTENDED DATA command
absolutely MUST follow immediately until all bytes have been sent. The
EXTENDED DATA code is handy, as any number of eight-bit bytes may follow.
The data bytes must follow the true/complement rule, so will take eight
cycles per byte, with no pause between bytes until complete. The only legal
sequence that doesn't conform to the true/complement rule are the start
bits 1110 that lead the whole thing off, likely because the modules need
some way to tell when it's OK to start listening again.

A full transmission containing everything looks like this (see the end of
this section for the actual command codes):

   1 1 1 0  H8 /H8 H4 /H4 H2 /H2 H1 /H1  D8 /D8 D4 /D4 D2 /D2 D1 /D1 F /F
   (start)         (House code)                 (Unit/Function code)

So, to turn on Unit 12 of House code A, send the following:

   1 1 1 0   0 1 1 0 1 0 0 1   1 0 0 1 1 0 1 0 0 1  (House A, Unit 12)

then wait at least three full AC cycles and send it again, then wait three
and send:

   1 1 1 0   0 1 1 0 1 0 0 1   0 1 0 1 1 0 0 1 1 0  (House A, Function ON)

again wait three cycles and send it the last time. Total transmission
would have been 264 discrete bits (don't forget the 3-phase) and would take
53 cycles of the AC line, or about .883 seconds.

It's perfectly allowable to stack the Unit or Function codes together, so
sending Unit 2 Unit 3 Unit 12 ON (separated by 3 cycles minimum) will
turn on all 3 units. Stacking ON and OFF codes is annoying and flashes the
lights quickly (roughly 4 Hz).


X10 COMMAND CODES

         House Codes                         Unit/Function Codes

       H8  H4  H2  H1                        D8  D4  D2  D1   F

    A   0   1   1   0                  1      0   1   1   0   0
    B   1   1   1   0                  2      1   1   1   0   0
    C   0   0   1   0                  3      0   0   1   0   0
    D   1   0   1   0                  4      1   0   1   0   0
    E   0   0   0   1                  5      0   0   0   1   0
    F   1   0   0   1                  6      1   0   0   1   0
    G   0   1   0   1                  7      0   1   0   1   0
    H   1   1   0   1                  8      1   1   0   1   0
    I   0   1   1   1                  9      0   1   1   1   0
    J   1   1   1   1                 10      1   1   1   1   0
    K   0   0   1   1                 11      0   0   1   1   0
    L   1   0   1   1                 12      1   0   1   1   0
    M   0   0   0   0                 13      0   0   0   0   0
    N   1   0   0   0                 14      1   0   0   0   0
    O   0   1   0   0                 15      0   1   0   0   0
    P   1   1   0   0                 16      1   1   0   0   0
                           All Units Off      0   0   0   0   1
                            All Units On      0   0   0   1   1
                                      On      0   0   1   0   1
                                     Off      0   0   1   1   1
                                     Dim      0   1   0   0   1
                                  Bright      0   1   0   1   1
                          All Lights Off      0   1   1   0   1
                           Extended Code      0   1   1   1   1
                            Hail Request      1   0   0   0   1   Note 1
                        Hail Acknowledge      1   0   0   1   1
                             Pre-Set Dim      1   0   1   X   1   Note 2
                           Extended Data      1   1   0   0   1   Note 3
                            Status is On      1   1   0   1   1
                           Status is Off      1   1   1   0   1
                          Status request      1   1   1   1   1   Note 4

Note 1:  Hail Request is transmitted to see if there are any other X10
         compatible transmitters within listening range.

Note 2:  In a Pre-Set Dim function, the D1 bit represents the MSB of the
         level and the 4 House code bits represent the 4 least significant
         bits. No known X10 device responds to the Pre-Set Dim function.

Note 3:  The Extended Data code is followed by eight-bit bytes which can
         be any data you might want to send (like temperature). There
         must be no delay between the Extended Data code and the actual
         data bytes, and no delay between data bytes.

Note 4:  The X10 RF to AC Gateway model RR501 is a two-way module. If the
         RR501 is addressed by transmitting its House Code and Unit Code and
         then the STATUS REQUEST is transmitted, the RR501 will respond by
         transmitting Status ON if it's turned on, or Status OFF if it's off.


RECOMMENDED SPECS TO ENSURE RELIABLE COMMUNICATION TO ALL X10 DEVICES:

  Carrier Oscillation Frequency         120KHz +/- 5%  (s/b 2%, but 5% OK)

  Zero Crossing Detection               100uS +/- 100uS

  Width of Transmitted Carrier          1mS +/- 50uS

  Transmitter output power              60 mW average (5V pk-pk into 5 ohms)

  Isolation Voltage                     2500V RMS. 60Hz for 1 min.


<FAQ SECTION 4>

SECTION 4:  PROGRAMMING DETAILS FOR CP290 HOME CONTROL INTERFACE
================================================================

Reference:  X10 CP290 Home Control Interface Programming Guide for
Advanced Programmers

The CP290 Home Control Interface communicates with the host computer via a
simplified RS-232 interface. Serial communication takes place at 600 baud,
eight data bits, no parity, and one stop bit. The reference recommends a
pause of one millisecond between transmitted bytes, although in many
applications this seems not to be required. This probably depends on the
efficiency of the serial communications software used to send data to the
interface.

The serial connector on the CP290 is a five pin DIN connector. As seen
from the back of the interface, the pinouts are as follows:

            5 - no connection  *       *  1 - no connection
          4 - data to computer  *     *  2 - data from computer
                                   *
                             3 - signal ground


There are eight possible commands that the computer can send to the CP290.
Each command starts with 16 hex FF bytes (each 0xff, or eight ones) for
synchronization purposes. These are followed by the command code 0-7 and
then a variable number of bytes as required by the syntax of each command.
The interface requires a checksum of data bytes that follow the command
code (see details for each command for exceptions) as the last byte in a
command.

The interface responds to each command with 6 hex FF bytes (each 0xFF, or
eight ones) for synchronization purposes. This is followed by a status
byte, and depending on the command, other information. The interface
generates a checksum for all bytes following the status byte and sends it
as the last byte in a reply to a command.


COMMAND 0 - SET INTERFACE BASE HOUSE CODE

The CP290 maintains a value called the base house code, which defaults to
house code A on power up. This is equivalent to setting the house code on
other X10 controllers; the eight buttons on the CP290 control units 1-8 on
or off for the base house code. Note that setting the base house code with
this command will clear all data in the interface.

Command syntax (computer to interface):

        bytes 0-15:      1111 1111 - synchronization
                16:      0000 0000 - command 0
                17:      HHHH 0000 - base house code to set

               where HHHH =  0000 - house code M
                             0001             E
                             0010             C
                             0011             K
                             0100             O
                             0101             G
                             0110             A
                             0111             I
                             1000             N
                             1001             F
                             1010             D
                             1011             L
                             1100             P
                             1101             H
                             1110             B
                             1111             J

Return (interface to computer):

        bytes 0-5:      1111 1111- synchronization
                6:      0000 000X - interface status

                where X = 0 - interface has lost all memory
                          1 - interface is OK


COMMAND 1 - SEND DIRECT COMMAND

It is possible to send X10 commands from the computer onto the power line
via the CP290. This is not particularly fast.

Command Syntax (computer to interface):

        bytes 0-15:      1111 1111 - synchronization
                16:      0000 0001 - command 1
                17:      LLLL FFFF - dimming level and function
                18:      HHHH 0000 - house code for this command
                19:      UUUU UUUU - unit codes bitmapped 9-16
                20:      VVVV VVVV - unit codes bitmapped 1-8
                21:      CCCC CCCC - checksum

                where   LLLL = 1111 - dimmest (not quite full off)
                                ... - intermediate brightness values
                               0000 - brightest (not quite full on)

                        FFFF = 0000 - units off (*)
                               0001 - lights on, not appliances (*)
                               0010 - turn on
                               0011 - turn off
                               0100 - if light off, turn on full; in any
                                        case, dim to full off. Responds as
                                        0011 (*)
                               0101 - if light off, turn on full; else
                                        brighten to full; then dim LLLL
                                        (LLLL+1?) steps. Responds as 0100.
                               0110 - if light off, turn on full; else
                                        brighten by LLLL+1 steps. Responds
                                        as 0101. (*)
                               0111 - no obvious effect. Responds as 0110.
                               1000 - no obvious effect.
                               1001 - no obvious effect.
                               1010 - no obvious effect.
                               1011 - no obvious effect.
                               1100 - no obvious effect. Responds as 1011.
                               1101 - no obvious effect. Responds as 1100.
                               1110 - no obvious effect. Responds as 1101.
                               1111 - no obvious effect. Responds as 1110.

                                where (*) indicates behavior undocumented
                                        in the reference

                        HHHH - as for Command 0

                        UUUU UUUU - units bitmapped as
                                9 10 11 12 13 14 15 16

                        VVVV VVVV - units bitmapped as
                                1 2 3 4 5 6 7 8

                        CCCC CCCC - sum of bytes 17-20

Return (interface to computer):

        bytes 0-5:      1111 1111 - synchronization
                6:      0000 000X - interface status
         (pause while X10 command is sent onto power line)
             7-12:      1111 1111 - synchronization
               13:      0000 000X - interface status
               14:      HHHH FFFF - house code and function
               15:      UUUU UUUU - unit codes bitmapped 9-16
               16:      VVVV VVVV - unit codes bitmapped 1-8
               17:      HHHH 0000 - base house code
               18:      CCCC CCCC - sum of bytes 14-17

               where all values are as explained above; response function
                        codes are same as command function codes except as
                        noted


COMMAND 2:  SET INTERFACE CLOCK

This command sets the internal clock in the CP290.

Command syntax (computer to interface):

        bytes 0-15:      1111 1111 - synchronization
                16:      0000 0010 - command 2
                17:      00mm mmmm - minutes 0-59
                18:      000h hhhh - hours 0-23
                19:      0ddd dddd - bitmapped day of week Sun - Mon
                20:      CCCC CCCC - sum of bytes 17-19

                where ddd dddd is day of week bitmapped as
                                Sun Sat Fri Thu Wed Tue Mon

Return (interface to computer):

        bytes 0-5:      1111 1111 - synchronization
                6:      0000 000X - interface status


COMMAND 3a:   SEND TIMER EVENT TO INTERFACE

This command sends a timer event to the interface. The computer can then
be disconnected and the event will be sent over the power line as X10
commands at the appropriate time. Events are stored eight bytes per event
in locations 0-1023 in the 2K RAM inside the interface.

Command syntax (computer to interface):

        bytes 0-15:      1111 1111 - synchronization
                16:      0000 0011 - command 3
                17:      AAAA AAAA - LSB of event address
                18:      0000 00AA - MSB of event address
                19:      NNNN MMMM - mode
                20:      0ddd dddd - bitmapped days Sun - Mon
                21:      000h hhhh - hour 0-23
                22:      00mm mmmm - minute 0-59
                23:      VVVV VVVV - bitmapped unit codes 1-8
                24:      UUUU UUUU - bitmapped unit codes 9-16
                25:      HHHH 0000 - house code for this event
                26:      LLLL FFFF - level and function
                27:      CCCC CCCC - sum of bytes 19-26

                where    0000 00AA AAAA AAAA (bytes 18 and 17) =

                         0000 0000 0000 0000 for event 0
                         0000 0000 0000 0100 for event 1
                         0000 0000 0000 1000 for event 2
                         .... (increases by 8 for each event)
                         0011 1111 1111 1100 for event 127


                         MMMM = 0000 - clear
                                0001 - ?
                                0010 - tomorrow only then clear
                                0011 - ?
                                0100 - today only then clear
                                0101 - ?
                                0110 - ?
                                0111 - ?
                                1000 - at exact time
                                1001 - at approximate time
                                1010 - ?
                                1011 - ?
                                1100 - ?
                                1101 - ?
                                1110 - ?
                                1111 - ?

                         NNNN = MMMM                  - program event
                         NNNN = MMMM = 0000           - clear event
                         NNNN not = 0000; MMMM = 0000 - store event but
                                   put it on hold (will not take place)

        Actually, setting for NNNN and MMMM is a bit vague. The reference
        indicates that NNNN = 0 and MMMM is function code as shown above.
        The software provided with the CP290 uses NNNN = MMMM except when
        "freezing" an event (deactivating it, but not erasing it). Frozen
        events also have UUUU UUUU = VVVV VVVV = 0. It's not clear how a
        frozen event knows what units it is to control. Not clearing the
        unit mask confuses the standard CP290 software...

Return (interface to computer):

        bytes 0-5:      1111 1111 - synchronization
                6:      0000 000X - interface status


COMMAND 3b:  SEND "GRAPHICS DATA" TO INTERFACE

In the 2K RAM of the interface, locations 1024 through 1535 are accessible
from the external computer, but are not used for events or any other
purpose by the interface. In the CP290 these are referred to as the
locations for graphics data. For each of 256 possible units, the memory
locations could be used to indicate (under control of an external program)
the on/off condition of a unit, or the type of unit it is (possibly an
index to a graphics icon). This command writes data from the computer two
bytes at a time to these memory locations in the interface.

Command syntax (computer to interface):

        bytes 0-15:     1111 1111 - synchronization
                16:     0000 0011 - command 3
                17:     AAAA AAA0 - LSB of data address
                18:     0000 0AAA - MSB of data address
                19:     GGGG GGGG - data byte 0
                20:     GGGG GGGG - data byte 1
                21:     CCCC CCCC - sum of bytes 19 and 20

                where   0000 0AAA AAAA AAAA(bytes 18 and 17) =

                        0000 0100 0000 0000 for data pair 0
                        0000 0100 0000 0010 for data pair 1
                        ... (increases by 2 for each subsequent data pair)

                        GGGG GGGG - can be anything relevant to the
                                        external program, since this data
                                        is not used by the interface

Return (interface to computer):

        bytes 0-5:      1111 1111 - synchronization
                6:      0000 000X - interface status


COMMAND 4:  GET CLOCK TIME AND BASE HOUSE CODE FROM INTERFACE

This command reads the time from the internal interface clock and also gets
the current base house code. It is an innocuous way of testing for the
presence of the interface, and to see if it has lost its memory since the
last time events were downloaded to it. If there is no reply to this
command after several seconds, the computer could assume that the interface
was not (properly) connected.

Command syntax (computer to interface):

        bytes 0-15:     1111 1111 - synchronization
                16:     0000 0100 - command 4

Return (interface to computer):

        bytes 0-5:      1111 1111
                6:      0000 000X - interface status
                7:      00mm mmmm - minute (0-59)
                8:      000h hhhh - hour (0-23)
                9:      0ddd dddd - bitmapped days Sun - Mon
               10:      HHHH 0000 - base house code
               11:      CCCC CCCC - sum of bytes 7-10


COMMAND 5:  GET TIMER EVENTS FROM INTERFACE

This command requests the interface to send to the computer the events that
it has stored in its memory.

Command syntax (computer to interface):

        bytes 0-15:     1111 1111 - synchronization
                16:     0000 0101 - command 5

Return (interface to computer):

        bytes 0-5:      1111 1111
                6:      0000 000X - interface status
                for( event = 0 ; event < 128 ; event = event+1 )
                {
                   if( event is not erased )
                   {
                         7:     NNNN MMMM - mode
                         8:     0ddd dddd - bitmapped days Sun - Mon
                         9:     000h hhhh - hour 0-23
                        10:     00mm mmmm - minute 0-59
                        11:     VVVV VVVV - bitmapped unit codes 1-8
                        12:     UUUU UUUU - bitmapped unit codes 9-16
                        13:     HHHH 0000 - house code for this event
                        14:     LLLL FFFF - level and function
                    }
                    else
                         7:     1111 1111 - indicates event in that
                                                location is erased
                }
        last byte:   CCCC CCCC - sum of all bytes for valid events
                                        starting with byte 7; does not
                                        include the 1111 1111 for locations
                                        where event has been erased


COMMAND 6:  GET "GRAPHICS DATA" FROM INTERFACE

This command requests the interface to send the "graphics data" that it has
stored in its memory. See COMMAND 3b above. Graphics data is not used in
any way by the interface.

Command syntax (computer to interface):

        bytes 0-15:     1111 1111 - synchronization
                16:     0000 0110 - command 6

Return (interface to computer):

        bytes 0-5:      1111 1111
                6:      0000 000X- status
                for( unit = 0 ; unit < 256 ; unit = unit+1 )
                {
                   if( graphics data for unit has been stored )
                   {
                        7:      GGGG GGGG
                        8:      GGGG GGGG
                   }
                   else
                        7:      1111 1111
                }
        last byte:      CCCC CCCC - sum of all data pairs for all units
                                        starting with byte 7; excludes the
                                        single 1111 1111s in cases where
                                        data for that unit has not been
                                        stored

COMMAND 7:  DIAGNOSTIC

This command tells the interface to run a self-check on its hardware and
firmware. Pin 4 on the interface goes low for 10 seconds; this may
generate extraneous characters that are detected by the attached computer.
At the end of this time, the interface sends its status if it can. Note
that this command will scramble or clear any data stored in the interface.

Command syntax (computer to interface):

        bytes 0-15:     1111 1111
                16:     0000 0111 - command 7

Return (interface to computer):

        bytes ?:        extraneous characters for 10 seconds
            0-5:        1111 1111 - synchronization
              6:        0000 000T - test status

             where 0000 000T = 0 - interface is OK
                               1 - interface has a fault


KEYBOARD COMMANDS

If X10 commands are sent using the keys on the top of the CP290, the
interface will send a report to the computer so it can keep track of the
status of units.

Report (interface to computer):

              0-5:      1111 1111 - synchronization
                6:      0000 000X - interface status
                7:      HHHH FFFF - house code and function
                8:      UUUU UUUU - unit codes bitmapped 9-16
                9:      VVVV VVVV - unit codes bitmapped 1-8
               10:      HHHH 0000 - base house code
               11:      CCCC CCCC - sum of bytes 14-17

                where FFFF is the function return code described for
                        Command 1 (SEND COMMAND DIRECT)


TIMED EVENTS

When the CP-290 sends X10 commands in accordance with an event programmed
into it, it will send a report to the computer so the computer can keep
track of the status of units. This report is in the same format as the
report for keyboard commands described above.


<FAQ SECTION 5>

SECTION 5:  MODIFICATIONS TO X10 HARDWARE
=========================================

WARNING:  Modifying X10 hardware as described in this section will void the
warranty of the hardware. Any modifications you do are at your own risk
and the results are entirely your own responsibility. You may end up
damaging the hardware beyond use. Remember, X10 devices are connected
directly to the power line, and can kill you. If you feel uncomfortable
about any of this, don't do it. The modifications in this section have been
tried by one or more people. They may not work for you, due to variation
in technical skill, or variation in X10 equipment lots. Again, you are on
your own; use at your own risk!


Q501. How do I modify appliance modules for momentary operation?

Normally appliance modules turn on and stay on in response to an ON
command, and off in response to an OFF command. In response to an ON
command appliance modules modified as described in this section will pulse
on then off twice, returning to the off position.

Procedure:

        1. Make sure module is off, unplug it and then take cover off.

        2. Locate 330K resistor below the IC chip. Remove it.

        3. Reassemble and test the module.


The module clicks twice because each X10 command is issued twice. Thus the
two commands causes two on/off cycles. If you would like the module to be
normally on, make sure that the module was left on before you start the
mod.


Q502. How do I add local dimming capability to wall switch modules?

There are X10 wall switches with local dimming capability, but these are
not as widely available and reasonably priced as the X-10 WS467. This
switch has a local on/off toggle and a slide button to lock it off. The
light it controls can be dimmed only from a remote X10 transmitter.

The difference in circuitry between the switches with and without local
dimming capability is minor. Those with local dimming capability have a
jumper wire where those without local dimming have a resistor and
capacitor. To convert a switch without local dimming to one with local
dimming, you will need to remove the resistor and capacitor and replace
them with a wire. You will need  a jeweler's flat-blade screwdriver, a
soldering iron, and a desoldering bulb or solder-up wick. You may find
needle nose pliers to be helpful as well.

Procedure:

        1. Make sure the switch is functioning properly before starting.

        2. Take the module apart all the way. Using the screwdriver,
press down on the tabs at the four corners of the back cover, and pop the
cover off. Be careful not to break the tabs. Remove the circuit board from
the case by prying the side of the case away from the side of the board
with the screwdriver far enough so that the PCB can clear the tabs which
hold it in place. As the PCB comes out, be careful not to lose the small
metal tab or the tiny spring-loaded rod which form part of the cutoff
switch. Also remove the plastic piece which holds the cutoff switch
assembly in place; removing the switch assembly now will make it easier to
reassemble the switch properly later. The following is a crude ASCII
diagram of the component side of the WS467 PC board, showing relative
locations of various components.



 |---------------------------------|
 |                                 |          TRIAC
 |                                 |            /
 |                                 |          /
 |                                 |        /   Notes: The WS467 has a small
 |                                 |      /     1/4 watt resistor soldered
 |                                 |    /       between holes 1 and 2, as
 | |---------------|               |  /         well as an electrolytic
 | |     I C       |           |-| |/           capacitor soldered between
 | |---------------|  o 1      | |/|            holes 3 and 4. Remove these
 |                2 o          |-| |            components and solder a
 |                    o            |            jumper wire between holes
 |                   3   o         |            1 and 3 to restore local
 |                      4          |            dimming.
 |                                 |
 |                                 |
 |                                 |
 |                                 |
 |   (Other circuitry omitted      |
 |     for clarity.)               |
 |                                 |
 |---------------------------------|

          WS467 PC Board
          Component Side

        3. Once the switch has been disassembled and the PCB removed from
the case, examine the component side of the board closely while referring
to figure 1. Locate the small electrolytic capacitor and 1/4 watt resistor
located just below and to the right of the IC on the board. They share a
common connection. Note that there is probably a larger 1/2 watt resistor
in close proximity to the correct one - make sure you pick the right
resistor. Now flip the board over and locate the 4 pads to which these two
components are soldered. After warming up your soldering iron, use the
solder wick or desoldering bulb to remove the solder from those pads, and
remove the components from the board. NOTE: you could also simply cut the
components off the board, leaving the lead stubs soldered in place, but
desoldering the components will result in a much neater job.

        4. Again referring to the diagram in figure 1, install a small
jumper wire between holes 1 and 3. Solder the wire to the pads on the foil
side of the PCB.

        5. Reassemble the case, pop the circuit board back in, and pop the
back cover on. Turn the switch over and look closely into the hole where
the cutoff switch assembly fits. There you will see a pair of small metal
protrusions as well as a shorter metal contact area. Replace the small
metal tab into its position between the two taller metal protrusions,
positioned so that the other end of the metal tab can contact the shorter
metal contact area. Pop the cutoff switch assembly back into place, making
sure that neither the tiny spring-loaded rod nor the metal tab fall out
while you do so.

        6. Install the switch in the wall, and test normal operations
(local on/off control, remote on/off/dim control, and the function of the
cutoff switch).

        7. Finally, test the local dimming function: Press and hold the
button on the switch. The light will come on, and then slowly cycle through
a bright-to-dim-to-bright sequence. Release the button when the desired
level of lighting is achieved. A quick tap on the button will turn the
light on and off.


Q503. How do I modify the maxi-controller to accommodate more than 16
units?

The maxi-controller controls 16 units on a single house code. For those of
applications with more than 16 units (and the thoughts of grouping units
together or gluing a dime to the house code select slot aren't that
appealing), a maxi controller can be made to control an alternate house
code with the addition of a momentary contact pushbutton.

The following procedure modifies the maxi-controller to use house code I
normally and control house code K with the push of a button.

Procedure:

        1. Open the maxi-controller. There is no need to remove the
circuit board.

        2. Install a miniature normally open momentary contact push button
switch (e.g. RS 275-1571A) in a hole *carefully* drilled in the back of the
top piece of the case so the switch will stick out the back when all is
done). Avoid the components and the mounting post. Position it roughly
behind the red LED on the Powerhouse brand of the maxi. Another way to
describe its location: If you have the standard label 1-16 in position, the
button goes behind approximately 12 (maybe a bit towards 11).

        3. Using a short jumper wire, solder one post of the switch to pin
7 of the IC (GI 8417) and the other lead to pin 10. Use as little heat on
the IC pins as possible to get a good solder joint without destroying it.

        4. Reassemble making sure nothing is shorting (jumper leads, etc.).

        5. Set house code rotary to position I and test units on house
code I. To operate house code K, push in pushbutton and hold it while
selecting the unit(s) and the operation (on,off,dim,bright,all lights on,
or all units off).

Note that the pins 7 to 10 mod will also allow you to control house codes
J/L, H/F, G/E, B/D, A/C, P/N, or O/M by changing the rotary switch.

Untried variations:  Using the chart below, you could connect via
pushbutton pins 7 and either 8, 9, 10, or 11 alternatively or more than one
if necessary to produce a desired combination. If you absolutely had to
produce a house code alternative where you need to turn a 1 into 0 instead,
you could use a normally closed pushbutton and cut a trace.

Maxi controller with GI 8417 IC (can jumper a "1" from pin 7)

 PIN     8   9   10  11
 ---    --  --   --  --

 J       0   0   0   0
 I       0   0   0   1
 L       0   0   1   0
 K       0   0   1   1
 H       0   1   0   0
 G       0   1   0   1
 F       0   1   1   0
 E       0   1   1   1
 B       1   0   0   0
 A       1   0   0   1
 D       1   0   1   0
 C       1   0   1   1
 P       1   1   0   0
 O       1   1   0   1
 N       1   1   1   0
 M       1   1   1   1


Q504. How do I modify the mini-controller to control more units?

This answer should be read in conjunction with the instructions for
modifying the maxi-controller in Q503.

Unfortunately, the truth table for the mini-controller appears to be all
different for that for the maxi-controller, and there isn't a real good
place to mount the pushbutton. Besides, if you really need to control a
bunch of units, you wouldn't have the mini-controller in the first place.

However, the following seems to apply:

Mini controller with 8925 IC (can jumper a "1" from pin 3)

 PIN     5   6    7   8
 ---    --  --   --  --

 M       0   0   0   0
 O       0   0   0   1
 E       0   0   1   0
 G       0   0   1   1
 C       0   1   0   0
 A       0   1   0   1
 K       0   1   1   0
 I       0   1   1   1
 N       1   0   0   0
 P       1   0   0   1
 F       1   0   1   0
 H       1   0   1   1
 D       1   1   0   0
 B       1   1   0   1
 L       1   1   1   0
 J       1   1   1   1


Q505. How do I modify the mini-controller to control all units for a
single housecode (i.e. all "bands")?

The X10 mini controller is capable of addressing four of the sixteen X10
unit codes. A slide switch on the controller allows the user to select the
"band" of units 1-4 or 5-8. A simple modification allows the selection of
two additional bands, 9-12 and 13-16. This covers the entire spectrum of
X10 units accessible from a single house-code.

This modification applies to the "Radio Shack" branded mini controller,
number 61-2677B. By visual inspection of the circuit board and internal
components, it appears that this modification also applies to "Stanley"
branded mini controller number 360-3090. It appears that both of these
units were manufactured for X10 for sale under the distributors' own brand
name, and are essentially identical inside.

There was an earlier model of the mini controller that was available from
Radio Shack, and possibly other sources. Legend has it that the old unit
was even easier to modify for access to all four bands. In fact, one
legend says that the unit was equipped with a four-band switch, two
positions of which were simply blocked off by the plastic bezel sticker
applied over the plastic cabinet. I don't know what the truth is, not
having one of the old mini controllers to study. What I do know is that
this modification was not developed for the old controller.

The old mini controller had four switches for the unit codes, plus
individual switches for ON, OFF, DIM, BRIGHT, ALL LIGHTS ON, and ALL UNITS
OFF. To turn on unit three, one would depress two switches:  3 and ON.

The new mini controller does not have ON and OFF switches apart from the
unit codes. Instead it has an ON and OFF switch for each of the four unit
codes. (In the case of the Radio Shack unit, there are four rocker
switches, up for ON and down for OFF. The Stanley unit has individual
switches for 1 ON, 1 OFF, 2 ON, 2 OFF, etc.)  Pressing one of these
switches sends both the unit code and the ON or OFF command. The user can
then follow up by using the DIM or BRIGHT switches, or the ALL LIGHTS ON or
ALL UNITS OFF switches.

Procedure:

        1. Unplug the unit and open the case by removing the four
phillips-head screws. Put both halves of the case in a safe place. When
handling the printed circuit board, observe the usual precautions for
static-sensitive devices.

        2. Locate the place where the existing "band" switch is located.
This is nothing more than a plastic handle on a metal slider that runs in a
trough molded into the top part of the case. The slider makes contact with
three large pads on the printed circuit board.

        3.The hardest part of the modification is finding a new switch to
use for the four-position band selector!  It is possible to use a two-pole
four-throw rotary switch. I'll let you figure out how to do the encoding
if you decide on that. I found a suitable switch in my junk-box and
mounted it in a position that replaces the old band switch. This entailed
some amount of cutting and gluing on the plastic case. I will assume that
you are doing the same. Find a small slide switch that has four positions.
It should have two rows of five contacts. As the switch is moved, it
should short two adjacent contacts at a time. Looking into the pins in the
back of the switch, one should see the following connection pattern for
each switch position:

     position 1         position 2         position 3         position 4
   +-------------+    +-------------+    +-------------+    +-------------+
   |1--2  3  4  5|    |1  2--3  4  5|    |1  2  3--4  5|    |1  2  3  4--5|
   |             |    |             |    |             |    |             |
   |A--B  C  D  E|    |A  B--C  D  E|    |A  B  C--D  E|    |A  B  C  D--E|
   +-------------+    +-------------+    +-------------+    +-------------+

Physically, the switch should fit in pleasingly with the rest of the panel.
This usually means that it should be rather small. This is a good time to
decide exactly where to put it. The most logical place is directly in place
of the existing band switch. This may require hacking away part of the
printed circuit board.

        5. Orient the printed circuit board in front of you, such that the
foil side is down, and the power cord attaches to the board on your left.
The big chip should be slightly right of center, and most of the components
will be near your belly. Make sure that the chip has 24 pins, and is
marked 78567. To your right of the chip is a small metal-can transformer.
Further right and up, should be an electrolytic capacitor, around 1000 mFd
at 25 V. The capacitor's negative lead is well marked. Locate the
positive lead.

        6. If the new switch does not physically replace the old one,
disable the old switch by removing the slider from it.

        7. Looking into the back of the switch, wire pin A to 4 to IC pin
11. Wire switch pin B to 3 to D to the + lead of the capacitor. Wire
switch pin C to IC pin 12. The result should look something like this:

      .------------.
      |            |
      |  +---------|---+
      |  |1  2 _3_ 4  5|
      |  |    /   \    |
      |---A  B  C  D  E|
      |  +------|--|---+
      |         |  |
      |         |  `-----> to capacitor +
      |         `--------> to IC, pin 12
      `------------------> to IC, pin 11


The intent of this circuit is to impress one of four binary codes on the
IC's pins 11 and 12. This tells the controller chip which band of X10
units to address. The logic levels to be presented to the chip are
provided by dead air and the + lead of the electrolytic capacitor. The
truth table is:

   unit     switch     switch    |  pin 11   pin 12
   band     position   shorting  |  sees     sees
   -----    --------   -------- -+- ------   -----
    1-4        1       1&2, A&B  |  cap      air
    5-8        2       2&3, B&C  |  air      cap
    9-12       3       3&4, C&D  |  cap      cap
   13-15       4       4&5, D&E  |  air      air


        7a. Rotary switch option. This version is untested, but should
work. It is for rotary switch lovers out there. Get a 2-pole 4-throw
rotary switch and wire it as follows:

        .------------------------------> to capacitor +
        |     |              |  |
        1_ 2  3  4        1_ 2  3  4
        |\                |\
          \- - - - - - - - -\
           \                 \
            O                 O
            |                 |
            |                 `--------> to IC, pin 12
            `--------------------------> to IC, pin 11

You probably want to avoid binary or BCD-encoded thumbwheel switches because
the base station coding scheme is offset slightly from normal binary coding
(and the switch output). You would have to relabel the switch positions, not
to mention blocking off the unused positions.

        8. Put the box back together. Screw it shut again before applying
power. Try it out.

([e-mail])


Q506. How do I modify the mini-controller to control only units 9-12 or
13-16?

Read in conjunction with Q505.

Procedure:

        1. Open mini-controller and pull back the circuit board. Be
careful not to let all the switch tops fall out.

        2. Locate the three pads underneath the slide switch. Notice that
the unmodified mini selects 1-4 or 5-8 depending on whether the center
position makes connection with one side or the other.

        3. To modify the mini to control only units 9-12, solder a jumper
such that all three pads connect together.

        4. To modify the mini to control units 13-16, simply remove the
slide switch.

Untried variation #1: If you solder the jumper as to not interfere with the
slide switch, then you could jumper just one side and then use the slide to
select 1-4 or 9-12 or .. jumpering the other side, 5-8 or 9-12.

Untried variation #2: If you mangle the slide switch so that it only has
the contacts on one side or the other, you could use the slide switch to
select 1-4 or 13-16, or .. removing the other side 5-8 or 13-16. A possible
problem here is that the half-mangled slide switch may not "sit right".


Q507. How do I modify the mini-controller for momentary operation?

The following answer comes from [e-mail]:

Description:

When a Mini-Controller is modified as below, your key presses are undone as
soon as you release the key. Thus pressing 'on' and then releasing, sends
an 'ON' and then a 'OFF' command. This is also true for 'All Unit'
commands. This mod only works on model 'MC460' Mini-Controllers, and not
the 'MC260' (If anyone knows how to identify the two, please post).

Procedure:

Inside the mini controller, connect pin 3 and 14 of the black IC marked
78567. You may want to make the connection with a little switch to return
the controller to normal mode.


Q508. How do I repair a "blown" X10 lamp module?

X10 lamp modules have a bad habit of dying premature deaths. Most of the
time, the problem can be traced back to a bad triac. Why the triac is the
weak link has been debated hotly. It is possible to "resurrect" the module
by simply replacing the triac. Caution must be stressed here; there are a
lot of triacs available, but whichever one you use must have an isolated
tab. The most universally available replacement is from Radio Shack, part
number 276-1000 [Does this part actually have an isolated tab?], or Digi-
Key part number L4008L6-ND. In addition to having an isolated tab, it also
has a higher rating than the original one, so will be less likely to fail.

If you don't know a triac from a mouse trap, you'd better not try to
replace it.


Q509. How do I defeat local control of lights and appliances?

A standard appliance or lamp module will turn itself on if the power switch
on the device it is connected to is switched on. This provides local
control. This is not always desirable, however. Local control depends on
the current draw through the module; if it exceeds a certain value, the
device turns on. Some devices (compact fluorescent lamps, for example)
seem to have low impedance and keep switching themselves on even when
explicitly turned off. This local control can be disabled for appliance
modules.

Procedure:

        Inside each module, there is an integrated circuit labeled "PICO-
570" or "PICO-536C"  Cut the lead that goes from pin 7 of this integrated
circuit to the hot AC connection.


Q510. How do I add a relay output to the power horn?

The following answer comes from [e-mail]:

Description:

I have always wanted to add a relay output to the power horn. With this
feature, I can switch on a more powerful outside bell, an autodialer, or
any other load upon detection of a violation. When I opened the case, I was
surprised to learn that unit was already designed to do just that, except
the necessary components have been left out. There even are two holes in
the back of the unit for screw terminals that are covered by a small
sticker. After tracing the circuit, I selected some replacements listed
below.

Procedure:

The procedure requires the installation of eight components that should be
commonly available. Open the case by removing the four screws in the back.
On the PC board you will see near the bottom (side away from the AC plug)
the silk screening for the relay output portion. Install the following
components (all resistors 1/4 watt with exceptions):

  R30 - 1Kohm (1/2Watt)
  R32 - 12Kohm
  R33 - 12Kohm
  R34 - 200Kohm
  R35 - 200Kohm
  D16 - Any Silicon Diode (not Zener)
  RL1 - Your relay (see note below)
  TR8 - 2N2222 Switching Transistor

For the screw terminals, you can use a set taken from an unused (X-10)
alarm sender, or you can decide on your own interface. The relay could be
tricky. I was lucky and was able to find a relay that fit after some
modifications. It does appear to me however that Radio Shack sells micro
relays that would fit.

Operation:

The relay will close as soon as the horn starts blaring (and vise versa).
Your current rating will certainly depend on the relay you choose. If you
are so inclined, you could even disconnect the piezo horns, and have a unit
that silently turns on a load upon an alarm violation.

Changing the reaction time of the Horn:

After some poking around I found out specifically how the Horn is
triggered. A capacitor is charged a small amount every time an ALL UNITS
OFF command is received after an ALL UNITS ON command. When this voltage
reaches 7.0 Volts, the Horn starts a-blarin'. This usually takes 20
seconds after the alarm system is triggered, an amount that I think is just
too long. The capacitor that determines the reaction time is C13, located
near pin 18 of the 78566 chip. The 'stock' value of this capacitor is
22uF, and it takes five transitions of the command to trigger the horn. By
using a 10uF capacitor this amount is reduced to only two needed
transitions. Summary:

        Standard Horn (22uF) trigger time is 20 seconds.
        Modified Horn (10uF)                 8  seconds.

The quick reaction time will hopefully cause the intruder to stop his break
in attempt sooner.

Effects of Combining the two Mods:

If you want the load that is switched by the relay be flashed on and off,
you can combine the two modifications. The on to off duty cycle can be
changed by changing C13. Actually what I have done is to socket C13, so
that I can open the case and easily change the reaction time of the horn.

Conclusion:

I ([e-mail]) am curious to know if anyone finds this mod
useful. Please let me know any questions or comments. Have fun, and I
will trust that you will not hold me responsible for your failures (only
for your successes 8-).

ALTERNATE VERSION:

One of the great shortcomings of the X-10 wireless security system is the
lack of an interface to external devices, like a strobe and/or siren, to
alert neighbors of a burglary or other emergency situation. The following
modification adds that capability.

When an alarm is activated, the base (receiving) unit wails its siren and
sends out alternately, at about one second intervals, the signals ALL
LIGHTS ON, ALL UNITS OFF. This has the effect of flashing all lights on
the same house code. You can buy a remote, plug-in power siren which has
been designed to trigger when it receives 4-5 on-off cycles, alternating
its two-tone horn in synch with the ON-OFF signals. However, it is not
suitable for outdoor installation.

As noted by others, the power siren circuit board contains space for an
optional external relay interface circuit, although units with this option
seem never to have been produced. It would provide a low-voltage contact
closure (30VAC, 2A max.).

In this note I will describe how to make the modification, based on
schematics from X-10 engineering and my own testing. This improves upon
earlier recommendations in the X-10 FAQ.

Modification:

Install the following components in their marked location on the circuit
board:

    R30      470 ohm 2 watts     do not allow to touch other components
    R31      2.7 K   1/2 watt    just fits: do not substitute or leave out
    R32      2.7 K   1/4 watt
    R33      100 K   1/4 watt
    R34      100 K   1/4 watt
    R35      150 K   1/4 watt
    R36      1 K     1/4 watt
    C18      10 uf   16 volts    + on board is marked with a diamond
    D16      1N4001  1 AMP diode
    TR8      TEC9014 (almost any 100ma NPN switching transistor will work)
    RL1      5 volt, 72 ma DIP relay, Radio Shack #275-243

Remove R8 (or just clip the leads). There may be a resistor in parallel
with R8, remove it also. This was used to keep the unregulated and
unloaded + supply from floating up too high, and is now taken care of by
R31.

Activated (and unmodified), the unit consumes about 70ma, powered on the -
side by a 100ma regulator. The relay modification consumes an additional
70 ma, over-taxing the power supply and regulator. Even though it will
still work for a brief time when activated, you risk having the regulator
shut-down or the transformer overheat. To get reliable operation within
safe-area limits, change the wiring to the piezo elements. The unit comes
from the factory in which all four elements are wired in parallel. Change
the wiring so that they are in a series-parallel configuration, reducing
their current drain from 50ma to 12.5ma, and reducing their total sound
level from 105db to 99db.

             --| |--    --| |--
          __/       \__/       \__      (piezo element wiring change)
            \       /  \       /
             --| |--    --| |--

You should maintain consistent polarity when rewiring the elements, and if
you are clever, you can do it by removing one brown wire at the top, switch
the polarity of the other brown wire at the top, and use the wire you
removed to relocate and extend the blue wire to the opposite side (cover
the exposed connection). Since you are going to hook up an external siren
presumably, the loss of indoor volume should not pose a problem (I think
it's too loud anyway).

Finally, you need to install screw terminals in the slots provided. I used
terminals taken from an X-10 door/window sensor in which I permanently
soldered the wires connecting to the magnet. Before installing them, you
must break off the side tabs which are on top and next to the screw,
otherwise the rear cover of the case won't fit. They don't quite stick up
as high as I'd like, so if anyone has a better source of screw terminals
I'd like to know. Now, remove the adhesive cover plate on the rear cover,
and write in red marker next to the terminals "30 volts, 2 amp max."

Please send corrections, suggestions, experience to <[e-mail]>.


Q511. How do I change the crystal in my CP290?

From a post by [e-mail]:

  I wondered about the accuracy of the internal clock in the CP-290.
  Necessity being the mother of invention, I have figured out how to increase
  the accuracy at least tenfold. Instead of drifting 30 seconds per
  week, my CP-290 now drifts less than 30 seconds a year.

  The CP-290 is clocked by a two-transistor crystal oscillator running at
  32.768 kHz. The power consumption of this oscillator is very low, which
  allows the CP-290 to run on battery backup for long periods. This
  oscillator is used to run the clock whether or not it is connected to AC
  power, i.e., the power line frequency is not used.

  To open the CP-290, unplug it and remove the battery. Next, remove the
  four screws holding the case together, one in the battery compartment and
  three under the rubber feet in the remaining corners. Remove the battery
  compartment and the screw near the power transformer that holds the main
  circuit board in place. When removing the main circuit board, watch out
  for the ribbon cable. It's pretty stiff, and the wires might break if you
  flex it too much.

  To improve the accuracy of the clock, I removed the original 100 ppm watch
  crystal and replaced it with a 20 ppm part (Digi-Key sells several).
  Next,I removed 33 pF capacitor C17 and replaced it with a 15 pF fixed
  capacitor in parallel with a 5-15 pF variable capacitor. I used NPO
  ceramic capacitors for maximum temperature stability.

  The oscillator circuit is located along the right side of the circuit
  board, about halfway between the ribbon cable and the battery compartment.
  The crystal is a small cylinder about 1 cm long and a few mm in diameter,
  and is covered by a blob of silicone to keep it in place. After installing
  the new parts, I removed the solder flux with alcohol so the stray
  capacitance of the flux wouldn't affect operation.

  To trim the oscillator, I used a frequency counter with 0.1 ppm accuracy.
  The clock signal can be probed at the end of R35 nearest to the battery
  compartment, or at wire jumper L21 near tuned transformer TC3, or on pin 39
  of the 80C48 microcontroller IC1.

  People who don't have access to a good frequency counter/standard will have
  to trim the oscillator the old fashioned way: by trial and error. If this
  is the case, you might want to program the CP-290 to turn off a non-
  existent module once an hour. The LED on the front panel will blink each
  time the CP-290 transmits, which will allow you to determine whether the
  clock is drifting.

  When adjusting the frequency, keep the CP-290 at the same temperature at
  which it will normally be operated, and allow the circuitry to warm up for
  at least 10 minutes first. It doesn't matter whether you run it on battery
  power or AC because the oscillator's supply voltage is regulated. I
  recommend using battery power for safety.

  You may have to use different capacitor values depending on how far and in
  what direction the frequency is off. Lower values of C17 make the
  oscillator run faster, and higher values make it run slower. If you make
  C17 too small, the oscillator won't run at all. You can tell whether the
  oscillator is running because the front panel LED will blink every few
  seconds when the CP-290 is on battery power. If it doesn't blink, the
  oscillator isn't running. Also, if you try to change the frequency too
  much, the oscillator will become unstable and drift with temperature. This
  happened to me with the original crystal, which is why I replaced it with a
  better one.


Q512. How do I repair a broken wall switch module?

From a post by Edward Cheung:

In most cases, the failure was in a hiwattage resistor near the 'bottom'
of the module. Look at how a wall switch is normally mounted inside a
wall box.  Call the part closest to the floor the 'bottom'.  When you
disassemble the wall switch, look for a 1/2 watt ~68Ohm resistor near
the bottom of the module.  If it has a brown crack on it, you know that
you have located the overheated/dead part.  Replace it with a 1 watt
unit.


</FAQ BODY>

</FAQ>