MOBILE MAP PLUS SYSTEM WITH MICROCONTROLLER OPERATION

DESIGN CRITERIA



September 27, 1993



ENCODER



	INPUT SCAN



	64 input same as current system

	Provide shorting jumpers for alarm input power like RANS board.



ALARM CODING



Send FSK preamble for lock.

Send alarm message twice.

Send parity check.

Send watchdog signal every five minutes (as current system).

Send watchdog signal only - no alarm signals.



OUTPUTS



600 ohm transformer with keying signal (same as now) - screw terminals.

Low impedence output, no keying (for Motorola interface).

To DB 15 on circuit board.

Auxiliary input and output for future tone signalling.

Separate keying output for Motorola - to DB 15.

Test output (no keying for testing mobile display - to DB 15)

Can we have jumper to show when test map is connected?

Ok to send input from Motorola - on DB 15 

( "0" = OK to send, 0 voltz).

Request to send output for Motorola - on DB 15.

("1" = +3 volts, "0" = 0 volts)

Time out after x seconds and send signal anyway.



DIAGNOSTIC LAMPS AND CONTROLS



Pot for setting deviation (output level) on encoder board.

Diagnostic lamps: 

Power on

Request to send

Clear to send

Sending alarm







POWER SUPPLY



Same as current system.

Provide battery plug and screw terminals like RANS board.



TEST FUNCTIONS



Two test conditions possible:



1. 	Press test button for normal send of alarms.

	For Motorola watch diagnostic lamps.



2.	When testing mobile displays plugged into encoder board.

Provide jumper on DB 15 to send input signal only.



MOBILE DISPLAY - DECODER



INPUT SIGNAL



Same as now - input from radio.

Capacitor coupled (for Motorola).



ALARM CODING



Look for FSK lock.

Receive two transmissions.

Compare parity.

Compare two transmissions.

If valid signal, illuminate alarm lamps.

Watchdog every 7 minutes as current system.



DIAGNOSTIC LAMPS



INT - interference (radio modules only)

FSK LOCK - all models

VALID ALARM - all models

WATCHDOG LAMP, with timeout as current system.



TEST FUNCTIONS



Lamp test same as current system.

System test - sequentially generate alarm signals to illuminate each alarm lamp.



LAMP DRIVERS



Output matrix, if possible.

Wire for DIP plugs to match current lamp wiring.

Red lamps flash and audible sounds (same as now).

Green lamps solid on (same as now).



AUDIBLE ALARM



Same as current system.

Put plug on board for remote audible mounting.



HORN RELAY



Same as current system.

	

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(c) CDT, 1993