(TXT) View Source
# RAD DATA COMMUNICATIONS
MTM-20 (V.36, DC POWER)
Card Type Modem (synchronous)
Chipset Unidentified
Transfer Rate 32/64Kbps
Data Modulation QAM
Data Bus Serial
(IMG) IMG 1
+------------------------------------------------------------+
| CONNECTIONS |
|------------------------------------------------------------|
| Function | Label | Function | Label |
|----------------------+-------+---------------------+-------|
| DC power in | CN1 | Analog loopback | SW2 |
| | | test switch | |
|----------------------+-------+---------------------+-------|
| V.36 serial port | CN2 | Remote digital | SW3 |
| | | loopback test | |
| | | switch | |
|----------------------+-------+---------------------+-------|
| Line out (see pinout | SC1 | Test pattern switch | SW4 |
| below) | | | |
|----------------------+-------+---------------------+-------|
| Local digital | SW1 | | |
| loopback 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. |
+------------------------------------------------------------+
+------------------------------------------------------------+
| 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 & |
| | ground | | 2 closed |
|---+------------------------------------+-------+-----------|
| | Signal ground not connected to | JP4 | Pins 2 & |
| | chassis ground | | 3 closed |
|---+------------------------------------+-------+-----------|
| » | 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 |
+------------------------------------------------------------+