World of Ham Radio 1997/WOHR97_AmSoft_(1997-02-01).iso/sat/sat_14/amsoft.iii

Text File | 1997-02-01 | 19KB | 415 lines

                    FODTRACK Satellite Tracking System
                    ==================================

                               Version 1.6



                               User Manual
                               ===========



Introduction:
=============


FodTrack is a simple, straightforward program intended to control an azimuth-
elevation rotator like the Yaesu-Kenpro 5400/5600, and a transceiver, for any
kind of satellite orbits.

FodTrack runs in foreground, continuously displays what it is doing, uses no
special system resources, and is so simple to use that you will not have any
trouble trying to figure out what is going wrong when the silly satellites seem
to go in another direction than your antenna...

The rotator can be connected to any parallel port. LPT2 is a good candidate, as
it is often present and seldom used. Nonstandard parallel ports are welcome,
just you need to know the address. No IRQ is needed.

The radio can be connected to any serial port. Just the same as for the
parallel port, only the address needs to be known to be able to use any port.

FodTrack is best suited for those setups where a single PC runs a multitasking
environment, like DESQview, with the satellite software in one window, a BBS in
another, and your favorite game in the third. Just open a fourth window and put
FodTrack there, it will be happy.
You can also use an independent computer for FodTrack. But you cannot run it in
background. If you want background operation, there are other programs
available for you.

FodTrack implements antenna flipping, so the satellites will not run against
your rotator's end stop. Rotator stop position can be south or north.

FodTrack cannot drive the rotator against it's stop position. The limits are
set in hardware, so even if your computer goes crazy, locks up, or whatever,
your rotator will not be damaged by beeing driven against a mechanical end
stop.

It can run under manual or automatic control. In automatic mode, a skeduler
like WA2N's SatSked can provide the commands. Two modes for automatization
are provided: In the preferred one, FodTrack runs continuously and is
controlled via a command file; in the alternative one, FodTrack is called for
a specific satellite, and aborts after one pass.

You can use FodTrack to control only your rotator, only your radio, or both.
Control for Yaesu FT736, Kenwood TS790 and several Icom radios is implemented.
IK3NWV tested it on a TS790, while IK0XBQ made the Icom test with an IC820.
Thanks to them for the beta testing. On the FT736 I tested it, and I'm using it
permanently since several months with that radio.
Probably it will run with other Kenwood radios, and perhaps also with other
Yaesu radios, but this has not yet been tested.




Copyright:
==========

FodTrack is free for noncommercial use. If you want to reward me somehow, write
a piece of useful software and put it in the public domain!


Disclaimer:
===========

FodTrack is provided without any guarantee that it will really do anything of
all the nice stuff this document says. But please, if you find a bug, tell me,
so I can fix it for the next version.

Error handling is not yet very complete. Be careful. In many situations the
program is case-sensitive.



Setting it up:
==============

This is VERY easy. Copy the FODTRACK files to a directory of your choice. You
can also maintain the kepfile there, but if you prefer you can use a kepfile at
some other place.

Edit the FODTRACK.CFG file to reflect conditions at your station. The file
explains itself.

Edit the FODTRACK.FRC file according to the satellites and frequencies you want
to use. Do not include those birds for which you don't want automatic
transceiver control. In this file you may tweak the frequencies. Many radios
are not exactly on spot, so specially for PSK RX, you will need to fine-tune
the frequencies in this file.

If you will run the program from somewhere else, you need a path to the
FodTrack directory.

The kepfile must be in 2-line format, with the satellite name appearing above
each 2-line block. Title lines are no problem. They are not needed, but they do
not disturb.


Running it:
===========

Execute FODTRACK.EXE. The program will come up, read its configuration file,
and then it will read the command file (FODTRACK.CMD). The default command file
says "NONE", so the program will stay idling. That's a good time to look around
the screen:

You will see a status display, which says what the program is doing. It can be
idling, waiting for a satellite, tracking it, calculating AOS and LOS while
guessing if it is convenient to flip the antenna over, or calibrating the
rotator.
There is a nice clock, ticking away your valuable seconds; also there is a line
telling you that the satellite selection is automatic, and several windows
without any data in them. They will come to live when you select a satellite.
There's also a small reminder for the commands you have available. Please note
that three of these commands are only available while in manual mode.
During AOS-LOS calculation the keyboard is dead.


Now let's play a bit: Type the letter m to get the program into manual mode,
then t to start tracking a satellite. The program will ask you which satellite
you want. Enter it's name exactly as it appears in the kepfile, otherwise
FodTrack will be very unhappy with you. For example, type KO-23.

The program reads the kepfile, and tells you the age of KO-23's keps in the
proper window. It will also tell you if you can get good tracking precision
with those keps, or if you should get new ones.
Then it calculates AOS and LOS times (for the novice: AOS means Acquisition
Of Signal and LOS is Loss Of Signal) If you haven't disabled flipping, FodTrack
also looks into it's crystal ball, to see if the bird will run against your
rotator stop on the next pass. If so, it will tell you after a while that the
antenna will be "flipped". If not, it will be on the "normal" side. If you
chose to park your antennas in the configuration file, then the "Flipped" or
"Normal" display will be overrun by the word "Parked".

The AOS, LOS and flipping calculation takes only a few seconds if you have a
coprocessor, but it can take nearly a minute on slow non-coprocessor machines.

After flipping determination is complete, the program will start tracking the
bird. Every second, if the computer is fast enough, the position is updated.
If the AOS time is more than 2 minutes away, no data is sent to the rotator
nor to the radio.
When the great moment arrives, two minutes before AOS, the program will start
sending target position data to your rotator, indicating so in the rotator
status display. The two-minute allowance assures that the rotator has enough
time left to point at the satellite before it comes over the horizon. At this
time, the program will also start controlling your radio, and showing the
Doppler-corrected frequencies. If the FODTRACK.FRC file does not contain data
for the selected satellite, then the program will not access the radio, and
will display Doppler correction in PPM (parts per million). This is useful for
manual tuning of analog satellites.

If the rotator is not flipped, azimuth and elevation on the rotator are the
real ones. If the program had to flip the antennas, azimuth is 180 degrees
shifted and elevation starts backwards from 180 degrees.

If you selected a stepsize of zero degrees in the configuration file, then the
program will send the rotator postition to the interface every second. In this
case, the rotator will move in fine steps, their size beeing given by the
dead-band in the interface and the stepsize of the D/A converter (256 steps).
If you selected a bigger stepsize, FodTrack will freeze the rotator until the
position error is half as big as your selected stepsize. Then it will move the
rotator a full step in the proper direction. If your antennas are fairly broad,
you can use this feature to reduce wear and noise. The recommended stepsize
is about half of your antenna beamwidth.

When the satellite goes below the horizon, the rotator output is frozen, the
program stops controlling the radio and calculates flipping for the next pass,
then starts waiting for the bird to come up again.
If you selected parking, the antennas will then be parked. Otherwise, they will
stay in the position the satellite left them, until the next pass is about to
start.


At any time except during AOS-LOS calculation, you can stop tracking a bird
using the s command, or quit using q. If you press a, the program will go back
into automatic mode, reading the command file and doing whatever it tells.




Rotator Interface:
==================

The program generates target position data as 8 bits for each azimuth and
elevation, using one of the printer control lines (pin 14) to tell if azimuth
or elevation is meant. 0 is az, 1 is el.

The schematic diagram of the interface is provided as a PCX file. This format
was chosen because in this particular case it gave the smallest file size among
all common formats, when compressed with PKZIP. The image is about 1700 x 1100
pixels; this seems to be the best compromise between file size and quality.

Please refer to the schematic in FODTRK22.PCX for this explanation:

A dual D/A converter (TLC7528 or similiar) is directly connected to the parallel
port. The port's strobe output is wired to the D/A's chip select input, pin 14
to the output select pin, and the 8 data bits to inputs 0 to 7.
The D/A converter is used in a reversed fashion, with the reference applied to
the outputs, and the output taken from the reference terminals. This allows
using a low-cost current-mode DAC in voltage-mode.

The analog outputs are compared to the rotator position output using
differential amplifiers, the output of this comparison beeing fed to two window
comparators driving the motors. The value of the (presently) 1M resistors
defines the rotator's dead range, so you can adjust it by modifying these
values. Lower resistance values cause the dead range to be  bigger, reducing
wear and tear, but worsening pointing accuracy. If you have stability problems
(oscillations), lower these resistances.

A switch is provided which allows disabling the FodTrack interface. When this
switch is ON, the interface will not allow you to move the rotator with the
pushbuttons on the controller. It will always hold the rotator to the position
stored in the interface. If you move the switch to the OFF position, you will
have full manual control over your rotator, while the interface still listens
to the PC and updates the D/A's internal registers.


As you can see, the loop is closed outside the PC, in hardware. This reduces
the processing load for FodTrack, and eliminates the possibility that a
computer crash may drive your rotator against it's end stop.

The program has no means to check if a rotator interface is connected, so you
can start it up without one.

The interface can be mounted in a small box. It is connected to the rotator
controller's 8-pin DIN connector, from which also the power is taken.

Please note that there are two standards in common use for the pinout of this
connector. The schematic diagram includes a picture of the proper pinout.



The program provides a calibration function which allows you to adjust your
rotator pots for correct ranging.

This sequence is valid for my interface circuits, and a Yaesu 5400 rotator:

- Assemble the interface, set everything up, load the program.
- Calibrate the rotator's full scale adjustments according to it's manual.
- Type c to get into the calibration routine.
- Enter 255 for both azimuth and elevation.
- Calibrate the rotator's output voltage adjustments to such positions that the
  rotator stays just before it's end stops (or limit switches) in both axes.
- Enter 0 for both azimuth and elevation.
- Check that the rotator turns around completely in both axes, without running
  against the limits. If it does run against a limit, something is wrong...
- Play around entering values of your choice, and make sure the rotator reacts
  correctly (compare the meters to what FodTrack says).




Radio Interface:
================

You can use the original RS232 interfaces, but these are costly. You can as
well use a simple level converter mounted inside a plug. Several firms offer
them at a much lower cost than the original ones, but it is still much cheaper
to build your own...

You really don't need a fancy MAX232 here. A simple CMOS chip, powered from 5
Volts, will do the job. Put a 100K resistor between the RS232 output and the
chip's input; that resistor together with the chip's clamping diodes will make
a very nice RS232 to TTL converter!

You can power the CMOS chip from a 78L05 regulator, fed through a few diodes
and a capacitor from the RS232 handshaking lines. FodTrack will "switch them
on" for you! You can put all these parts into an RS232 connector (even a 9-pin
shell is big enough, if you are careful...), to get a very nice and cheap
control interface.

Some radios use TRUE polarity, others need the RS232 signal inverted. Check the
docs of the radio, and use one or two gates of your 74HC04 accordingly.

Remember that for FodTrack you don't need data FROM the radio TO the PC, but if
you want this for some other program, just put the TTL signal into the PC's
RS232 input. I have never seen any port that does NOT work that way!

I'm providing the schematics of the adapters I use in my station. RS232Y.PCX
is the version for Yaesu, which I use on my FT736, while RS232K.PCX is for
Kenwood radios. I use that one for my TS450, and I hope it will run also on
the TS790, but I have not tested this.

I'm also providing a schematic for an interface which perhaps could get the
Guiness record for simplicity: just three components! This circuit does not
provide a "reply" connection for the radio, and it can be used only with radios
that have an input with pull-up, and use inverted signals. It works perfectly
well with FodTrack and the Yaesu FT736R, and will probably also work with
Icom radios (using another plug, of course...).
This circuit is in RS232SIM.PCX.



Ready made interfaces:
======================

For those who don't want to assemble their own interfaces, AMSAT-CE can provide
the circuits in FODTRK22.PCX and RS232SIM.PCX assembled and tested, ready for
"plug and play". Any funds collected go to our CESAR-1 project, a 9600 baud
Pacsat. If you are interested in this deal, write to Carlos Godoy, CE2HI, via
any of the following ways:

Mail:    AMSAT-CE
         P.O.BOX 803
         VINA DEL MAR
         CHILE

e-mail:  [e-mail]  (The e-mail adddress provided in previous
                                     versions of this file is no longer valid).

Fax:     [phone]

Cost, for the combination of the two interfaces, including shipping via
registered airmail, is about US$ 110. Unfortunately AMSAT-CE cannot charge
credit cards. The two interfaces can also be provided separately.



Automation:
===========

There are now two different ways for automatic tracking of multiple satellites.

The preferred mode is this:

Configure your skeduling program in such a way that it writes a FODTRACK.CMD
file into the FodTrack directory, containing the name of the satellite to
be tracked, exactly as it appears in the kep file. This CMD file should be
written two or three minutes before the start of the pass, to give FodTrack
enough time to do the crystal ball business and preset the antennas. The
easiest way to write these command files is simply to copy them from somewhere
elso into the FodTrack directory, using a COPY command inside the a batch file
you run at the start of a pass. For example, you can have a FODTRACK.CMD file
in your KO-23 directory, containing the text "KO-23" (without the quotes, of
course...). Into the BAT file you run at the start, you put the command
COPY C:\SAT\KO-23\FODTRACK.CMD C:\SAT\FODTRACK\FODTRACK.CMD

After the pass, the skeduling system should write a CMD file saying NONE, so
FodTrack stops.
Now you load FodTrack inside your multitasker. When your satellite skeduler
decides to run a pass, it calls the BAT file, which copies the proper
FODTRACK.CMD into the FODTRACK directory. When FodTrack reads the file within
the next second, it starts tracking the specified sat. After the pass, the
CMD file contents is changed to "NONE", and FodTrack goes to idle, waiting for
the next pass.

FodTrack checks the CMD file continuously, so it is mandatory to have a disk
caching program like SMARTDRIVE, or some hardware cache. Otherwise your hard
disk will complain. But anyway, nobody should be working without a cache these
days!

The alternative mode for automatization is simpler:

It consists just in configuring FodTrack for automatic exit after a pass (in
the CFG file), and calling it before each pass specifying the satellite on the
command line. For example, you use the command FODTRACK KO-23.
FodTrack will start up, wait for the specified sat, track it until the end of
the pass, and then quit. The command file is not read in this mode.

The disadvantage of this mode is that when FodTrack starts for a pass, it
doesn't know where the rotator is. This eliminates the possibility of selecting
flipping according to the status from the last pass, which is useful to reduce
rotator wear. In the preferred mode, with flipping and without parking, this
kind of rotator wear reduction works.

If you switch to manual mode after starting FodTrack with a sat on the
command line, it will then work in the normal way. If you then switch into
automatic mode, it starts reading the command file. But if you switch directly
from command line mode into automatic mode, the program will abort, because it
considers the pass finished.


In case of trouble:
===================

If you have any trouble with FodTrack, tell me, so I can fix the bugs for the
next version. Also I will do my best to act upon any suggestion for
improvement, if reasonable and possible to implement.

To contact me, send a message on KO-23, KO-25, UO-22 or AO-16. You can also try
through the terrestrial packet net, if my program shook your satellite antennas
to pieces. The address is [e-mail].

On Internet, you can reach me at [e-mail]. Be patient, I have access to
internet only every second week, because of my working schedule, and sometimes
I'm away for several weeks.

Is there anyone around who likes to use snailmail? If so, use this address:

Manfred Mornhinweg
Radio Club Coquimbo
Casilla 381
Coquimbo
Chile


A last word:
============

I'm not a professional programmer, so you are allowed to smile about my program
and me...