home *** CD-ROM | disk | FTP | other *** search
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- PD - POCSAG Decoder
-
- User Documentation
-
- Version 1.02 June 1995
-
-
-
-
-
-
-
-
-
-
- Contents
-
-
- 1. Introduction
-
- 2. Registration
-
- 3. Installation
-
- 4. Interfacing
-
- 5. Configuration
- 5.1 PD.INI
- 5.1.1 General Parameters
- 5.1.2 Function Codes
- 5.2 PAGERS.INI
- 5.3 REJECT.INI
-
- 6. Running the program
- 6.1 Command Line Options
- 6.2 Supported Keys
- 6.3 Status Line
- 6.4 Normal Mode
- 6.5 Debug Mode
-
-
-
-
- 1. Introduction
-
- PD, together with a receiver or scanner, allows the off-air decoding of
- POCSAG paging signals at either 1200 or 512 bits/second. This makes it
- extremely useful for the testing of paging transmitters and systems.
-
- Decoding of both numeric and alphanumeric pager data is supported, as is
- the hex dumping of raw POCSAG codewords.
-
- PD runs on an IBM PC or equivalent, anything from an 8086 upwards. It
- requires 512K of conventional memory and a small amount of hard disk
- or floppy. Hard disk is recommended.
-
- PD runs from DOS, running from Windows is not recommended.
-
-
- 2. Registration
-
- PD is freely distributed as a shareware version. This has a timeout of
- about 5 minutes, after which a registration message is displayed and
- the program exits. Also the logging of pager data to disk is disabled.
-
- To obtain a fully functional registered copy of PD send a cheque or money
- order for 20.00 pounds sterling to:-
-
- Peter Baston,
- 7 Allerton Close,
- Pen-y-ffordd,
- Clwyd,
- CH4 0NJ,
- U.K.
-
-
-
- 3. Installation
-
- In order to install the program copy the following files into a directory
- on a hard drive, or onto a floppy:-
-
- PD.EXE Pocsag Decoder program
- PD.INI Configuration file
- PAGERS.INI List of pager codes (7 digit RIC's) to be logged
- REJECT.INI List of pager codes to reject
- PD.TXT This documentation file
-
-
-
- 4. Interfacing
-
-
- The PD program requires serial POCSAG data to be applied to the CTS pin
- of one of the PC's COM ports. RS232 levels are required, ie at least +/-
- 3v. PD is insensitive to polarity, ie it doesn't matter which way up mark
- and space are.
-
-
- As POCSAG is transmitted as direct FSK of the VHF/UHF carrier the ideal
- way is to take the data direct from the discriminator, via a data slicer.
- The following circuit, however, has been fairly successful, taking audio
- directly from the receiver's speaker output:-
-
-
- 0.1 uF |\ +12v
- ---||-----------------------|- \|
- AF IN | |741 \
- ---- | | /--------------------- Data Out
- | \ ------|+ /| | CTS (pin 5/8)
- | / 100K | |/-12v |
- | \ | | GND ------ GND (pin 7/5)
- GND / ----/\/\/\----
- | | 100K
- | \ N.B. Pin Numbers for com port are
- GND / given as x/y, where x is for a 25
- \ 10K way, y for a 9 way.
- /
- |
- GND
-
- The +/- 12v for the op-amp can be derived from unused signals on the COM
- port (gives more like +/- 10v but works fine !):-
-
-
- TxD (2/3) --------------|<-------------------------------------- -12v
- | |
- RTS (4/7) --------------|<-------- GND - -
- | | _ + 1uF
- --------->|------- - - |
- Diodes 1N4148 | - + 1uF GND
- | |
- DTR (20/4) ------------->|-------------------------------------- +12v
-
-
-
-
- 5. Configuration
-
- 5.1 PD.INI
-
- The PD.INI file allows a limited amount of configuration of the PD program.
- Any text editor can be used to edit this file. The file is divided up into
- sections, headed by a name in square brackets, eg [general], [functions].
- In each section are parameters, set to a value with an "=" sign, eg:-
-
- logbeep=100
- func1=alpha
-
-
-
- 5.1.1 General Parameters
-
- These parameters come under the [general] heading. This version only supports
- one parameter in this section
-
- 5.1.1.1 logbeep
-
- This parameter allows the length of the "beep", sounded when a pager message
- is logged, to be set. It's format is:-
-
- logbeep=<number>
-
- eg:-
-
- logbeep=100
-
- Where <number> is the length of the beep in milliseconds. A value of zero
- turns off the beeping, this is the default.
-
-
- 5.1.2 Function Codes
-
- These parameters come under the [functions] heading. Four parameters are
- supported - func0, func1, func2 and func3. These allow the decoding of
- the pager data to be determined by the function code, transmitted in the
- address codeword. The format for setting these parameters is:-
-
- funcx=<string>
-
- Where <string> is one of:-
-
- alpha - The message will be decoded as alphanumeric ASCII
- data.
-
- numeric - The message will be decoded as BCD numeric data.
-
- raw - The message will be dumped in raw form, as hex
- codewords
-
- eg:-
-
- func0=raw
- func1=numeric
- func2=numeric
- func3=alpha
-
- The program defaults to decoding all function codes as "alpha" data.
-
-
- 5.2 PAGERS.INI
-
- This file contains a list of pager addresses to be logged and is simply
- a list of 7 digit RIC's, eg:-
-
- 1234567
- 0012345
- etc
-
- This file may contain up to 100 addresses. Every time one of these
- addresses is encountered it is highlighted on the screen, a beep is
- sounded if configured, and the page is logged to disk with a date/time
- stamp. The log filename is <RIC>.TXT, eg 1234567.TXT.
-
-
- 5.3 REJECT.INI
-
- This file contains a list of pager addresses to be rejected, eg to save
- screen clutter. This file has the same format as described in 5.3 above.
-
-
-
- 6. Running the Program
-
-
- 6.1 Command Line Options
-
- PD is run from the DOS prompt with the following format:-
-
- PD <-Px> <-B512>
-
- Where the command line options are:-
-
- -Px Use COM port x. Default is COM1.
-
- -B512 Forces 512 bits/second POCSAG decoding, default is 1200 bps.
-
-
- 6.2 Supported Keys
-
- The following keys are supported whilst PD is running:-
-
- ESC Exits the program
-
- F1 Toggles between NORMAL and DEBUG modes
-
- SPACE BAR Toggles PAUSE mode on and off
-
-
- 6.3 Status Line
-
- After PD starts up it displays a status line across the top of the screen,
- with a data area below. The status line is as shown below:-
-
-
- NORMAL COM1 1200 * PD Version 1.02 * PAUSE REJ / 09:30:57
-
-
- The items on the status line are described below, from left to right:-
-
- * NORMAL/DEBUG indicator - shows which mode PD is currently operating in.
-
- * COM port currently in use.
-
- * Current POCSAG bit rate.
-
- * Version of PD being used.
-
- * PAUSE indicator - appears when paused by the space bar.
-
- * REJ indicator - appears when a pager address matches one listed in
- REJECT.INI
-
- * Rotating signal indicator. Appears to rotate when data is being
- received on the correct pin of the COM port. This is no indication of
- good data, just that the levels are correct.
-
- * The current time from the PC's real time clock.
-
-
- 6.4 Normal Mode
-
- In NORMAL mode, as long as good POCSAG data is being received, lines of
- the following form are displayed:-
-
- [RIC] [Function Code] <data>
-
- eg:-
-
- 1234567 3 Please call 1234 - 5688
- 0345678 1 Test call
-
- [RIC] is the 7-digit RIC pager address
- [Function Code] is the transmitted function code 0,1,2 or 3
- <data> is numeric,alphanumeric or hex depending on the function code.
-
- The data field may overflow onto multiple lines.
-
- Before data is displayed in NORMAL mode the address codeword is checked
- for errors and must be error-free. Subsequent data codewords are not
- checked for errors. Some "garbling" of data may therefore occur if a
- good signal is not being received, although received RIC codes are
- guaranteed to be good.
-
-
- 6.5 Debug Mode.
-
- In Debug mode the raw POCSAG codewords are dumped to the screen in hex
- form, eg:-
-
- 7A89C197 7A89CI97 7A89C197 7A89C197 7A89C197 7A89C197 7A89C197 7A89C197
- 7A89C197 7A89C197 14083EE2 7A89C197 7A89C197 7A89C197 7A89C197 7A89C197
-
- Any codewords which do not pass the BCH and parity error checking are
- highlighted. This is very useful for checking the quality of the
- received signal.
-
-
- <<<<=====>>>>>
-
-
- ▄█████▄ ▄█████▄
- █ ▀█▀ █ █ ▀█▀ █
- ▀██▄██▀ ▀██▄██▀
- ▌▌█▐▐ ▌▌█▐▐
- █████████ █████████
- ███──────────────────────────────────────────────────────────███
- ███ L E E C H E D ███
- ███ F R O M ███
- ███ T H E F I L E A R C H I V E S O F ███
- ███ ■ ■ ■ ███
- ███ T H E D O J O B B S ███
- ███ 7 1 3 . 9 9 7 . 6 3 5 1 ███
- ███ HoMeSiTe oF THe QUaRaNTiNE iNFeCTiON CoLLeCTiON ███
- ███ NIRVANAnet(tm) 9:700/100 ███
- ███──────────────────────────────────────────────────────────███
- █████████ █████████
- ▌▌█▐▐ ▌▌█▐▐
- ▄██▀██▄ ▄██▀██▄
- █ ▀█▀ █ █ ▀█▀ █
- ▀█████▀ ▀█████▀
-