RAD DATA COMMUNICATIONS
=======================

   ASM-20 G.703

   Modem Type               Data (Synchronous)                    
   Maximum Data Rate        64Kbps                                
   Data Bus                 External                              
   Data Modulation Protocol Proprietary                           

<gopher://bitreich.org/I/th99/t/P-R/51531-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |   Purpose   | Location |        Purpose         | Location |
   |-------------+----------+------------------------+----------|
   | G-703       |   CN1    | Diagnostic test switch |   DIG    |
   |-------------+----------+------------------------+----------|
   | AC power    |   CN2    | Analog loopback switch |   ANA    |
   |-------------+----------+------------------------+----------|
   | Ground      |   GND    | Remote loopback switch |   REM    |
   |-------------+----------+------------------------+----------|
   | Receive     |   RCV    | Test pattern           |   PATT   |
   |-------------+----------+------------------------+----------|
   | Transmit    |   XMT    |                        |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                         CD SIGNAL                          |
   |------------------------------------------------------------|
   | Setting                     |             JP1              |
   |-----------------------------+------------------------------|
   | CD normal                   |      Pins 2 & 3 closed       |
   |-----------------------------+------------------------------|
   |>> CD forced high            |      Pins 1 & 2 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  CHASSIS TO SIGNAL GROUND                  |
   |------------------------------------------------------------|
   | Setting                    |              JP6              |
   |----------------------------+-------------------------------|
   |>> Connected                |       Pins 2 & 3 closed       |
   |----------------------------+-------------------------------|
   | Disconnected               |       Pins 1 & 2 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     ENABLE PUSHBUTTONS                     |
   |------------------------------------------------------------|
   | Setting                       |            JP5             |
   |-------------------------------+----------------------------|
   |>> DIG, ANA, REM, PATT enabled |     Pins 1 & 2 closed      |
   |-------------------------------+----------------------------|
   | Disabled                      |     Pins 2 & 3 closed      |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                       JITTER FILTER                        |
   |------------------------------------------------------------|
   | Setting                    |              JP8              |
   |----------------------------+-------------------------------|
   | Enabled                    |       Pins 1 & 2 closed       |
   |----------------------------+-------------------------------|
   |>> Disabled                 |       Pins 2 & 3 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     RECEIVE IMPEDANCE                      |
   |------------------------------------------------------------|
   | Setting                    |              JP4              |
   |----------------------------+-------------------------------|
   |>> 135omhs                  |       Pins 1 & 2 closed       |
   |----------------------------+-------------------------------|
   | Low                        |       Pins 2 & 3 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     TRANSMIT IMPEDANCE                     |
   |------------------------------------------------------------|
   | Setting                    |              JP3              |
   |----------------------------+-------------------------------|
   |>> 135omhs                  |       Pins 1 & 2 closed       |
   |----------------------------+-------------------------------|
   | Low                        |       Pins 2 & 3 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                       TRANSMIT LEVEL                       |
   |------------------------------------------------------------|
   | Setting                    |              JP2              |
   |----------------------------+-------------------------------|
   |>> 0dBm                     |       Pins 2 & 3 closed       |
   |----------------------------+-------------------------------|
   | -6dBm                      |       Pins 1 & 2 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                         V.54 DELAY                         |
   |------------------------------------------------------------|
   | Setting                    |              JP7              |
   |----------------------------+-------------------------------|
   |>> On                       |       Pins 2 & 3 closed       |
   |----------------------------+-------------------------------|
   | Off                        |       Pins 1 & 2 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     DIAGNOSTIC LED(S)                      |
   |------------------------------------------------------------|
   | LED  | Color  |  Status  |            Condition            |
   |------+--------+----------+---------------------------------|
   | PWR  | Green  |    On    |           Power is on           |
   |------+--------+----------+---------------------------------|
   | PWR  | Green  |   Off    |          Power is off           |
   |------+--------+----------+---------------------------------|
   | RTS  | Yellow |    On    |     Request to Send enabled     |
   |------+--------+----------+---------------------------------|
   | RTS  | Yellow |   Off    |    Request to Send disabled     |
   |------+--------+----------+---------------------------------|
   |  TD  | Yellow |    On    |  Modem is transmitting steady   |
   |      |        |          |              SPACE              |
   |------+--------+----------+---------------------------------|
   |  TD  | Yellow |   Off    | Modem is not transmitting data  |
   |------+--------+----------+---------------------------------|
   |  TD  | Yellow | Blinking |   Modem is transmitting data    |
   |------+--------+----------+---------------------------------|
   |  RD  | Yellow |    On    | Modem is receiving steady SPACE |
   |------+--------+----------+---------------------------------|
   |  RD  | Yellow |   Off    |   Modem is not receiving data   |
   |------+--------+----------+---------------------------------|
   |  RD  | Yellow | Blinking |     Modem is receiving data     |
   |------+--------+----------+---------------------------------|
   | DCD  | Yellow |    On    |     Carrier signal detected     |
   |------+--------+----------+---------------------------------|
   | DCD  | Yellow |   Off    |   Carrier signal not detected   |
   |------+--------+----------+---------------------------------|
   | TEST |  Red   |    On    |       Modem in test mode        |
   |------+--------+----------+---------------------------------|
   | TEST |  Red   |   Off    |     Modem not in test mode      |
   |------+--------+----------+---------------------------------|
   | ERR  | Yellow |    On    |     Errors in test pattern      |
   |------+--------+----------+---------------------------------|
   | ERR  | Yellow |   Off    |        Good test pattern        |
   +------------------------------------------------------------+