
RAD DATA COMMUNICATIONS

MTM-20 (G.703 RJ-45, DC POWER)

Card Type       Modem (synchronous)
Chipset         Unidentified
Transfer Rate   32/64Kbps
Data Modulation QAM
Data Bus        Serial

[Image]

                                CONNECTIONS

       Function           Label             Function              Label

  DC power in                  CN1       Analog loopback test      SW2
                                         switch

  G.703 port (see pinout       CN2       Remote digital            SW3
  below)                                 loopback test switch

  Line out (see pinout         SC1       Test pattern switch       SW4
  below)

  Local digital loopback       SW1
  test switch

            Note: Modem can be made to perform self-test by holding down
            SW2 and SW4. The DCD, TEST, and SQ LEDs should go on, and the
            RD LED should go off.

                                CN2 PINOUT

       Function          Terminal           Function            Terminal

  Not used                      1         Transmit line             5

  Not used                      2         Receive line              6

  Receive line                  3         Not used                  7

       Transmit line            4         Not used                  8

                                SC1 PINOUT

       Function          Terminal           Function            Terminal

  Ground                        1         Not used                  5

  Not used                      2         Transmit line             6

  Receive line                  3              Transmit line        7

  Receive line                  4

                        USER CONFIGURABLE SETTINGS

                  Setting                      Label         Position

  DCD forced high                               JP3         Pins 3 & 4
                                                              closed

  DCD normal                                    JP3         Pins 1 & 2
                                                              closed

  Signal ground connected to chassis            JP4         Pins 1 & 2
  ground                                                      closed

  Signal ground not connected to chassis        JP4         Pins 2 & 3
  ground                                                      closed

  FIFO connected to transmit line               JP6         Pins 1 & 2
                                                              closed

  FIFO connected to receive line                JP6      Pins 2 & 3 closd

  Line speed set to 64Kbps                      SW5         Position 4

  Line speed set to 32Kbps                      SW5         Position 3

                         TRANSMIT LEVEL

  Setting     JP5/A      JP5/B      JP5/C      JP5/D     JP5/E

   0dBm      Closed      Open       Open       Open       Open

   -3dBm      Open      Closed      Open       Open       Open

   -6dBm      Open       Open      Closed      Open       Open

   -9dBm      Open       Open       Open      Closed      Open

  -12dBm      Open       Open       Open       Open      Closed

               CLOCK SOURCE

       Setting               JP1

      Internal        Pins 1 & 2 closed

      External        Pins 3 & 4 closed

      Received        Pins 5 & 6 closed

                               LINE LENGTH

               Setting                               JP2

               0-10Km                         Pins 3 & 4 closed

               7-13Km                         Pins 1 & 2 closed

  Auto select (not yet implemented)           Pins 5 & 6 closed

                             DIAGNOSTIC LED(S)

    LED         Color          Status                 Condition

    PWR         Green            On                  Power is on

    PWR         Green            Off                Power is off

    RTS         Yellow           On              RTS signal is high

    RTS         Yellow           Off              RTS signal is low

     TD         Yellow           On           DSU is transmitting SPACE

     TD         Yellow           Off           DSU is not transmitting

     TD         Yellow        Blinking        DSU is transmitting data

     RD         Yellow           On            DSU is receiving SPACE

     RD         Yellow           Off            DSU is not receiving

     RD         Yellow        Blinking          DSU is receiving data

    DCD         Yellow           On            Carrier signal detected

    DCD         Yellow           Off         Carrier signal not detected

    TEST         Red             On              DSU is in test mode

    TEST         Red             Off           DSU is not in test mode

     SQ         Yellow           On            Signal quality is good

     SQ         Yellow        Blinking        Signal quality is poor or
                                            test pattern contains errors

