RAD DATA COMMUNICATIONS
ASM-20 V.35
Modem Type | Data (Synchronous) |
Maximum Data Rate | 144Kbps |
Data Bus | External |
Data Modulation Protocol | Proprietary |

CONNECTIONS | |||
Purpose | Location | Purpose | Location |
V.35 | 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 | ||
ANALOG LOOPBACK | |
| Setting | JP7 |
| » Enabled | Pins 1 & 2 closed |
| Disabled | Pins 2 & 3 closed |
BAUD RATE | |
| Setting | SW1 |
| 128Kbps | 0 |
| 112Kbps/144Kbps | 1 |
| » 64Kbps | 2 |
| 56Kbps/72Kbps | 3 |
| 48Kbps | 4 |
| 32Kbps | 5 |
CD SIGNAL | |
| Setting | JP3 |
| CD normal | Pins 1 & 2 closed |
| » CD forced high | Pins 2 & 3 closed |
CHASSIS TO SIGNAL GROUND | |
| Setting | JP10 |
| » Connected | Pins 2 & 3 closed |
| Disconnected | Pins 1 & 2 closed |
CLOCK SOURCE | |||
| Setting | JP1/A | JP1/B | JP1/C |
| » Internal | Closed | Open | Open |
| External | Open | Closed | Open |
| Receive | Open | Open | Closed |
ENABLE PUSHBUTTONS | |
| Setting | JP9 |
| » DIG, ANA, REM, PATT enabled | Pins 1 & 2 closed |
| Disabled | Pins 2 & 3 closed |
RECEIVE IMPEDANCE | |
| Setting | JP6 |
| » 135omhs | Pins 1 & 2 closed |
| Low | Pins 2 & 3 closed |
REMOTE LOOPBACK | |
| Setting | JP8 |
| » Enabled | Pins 1 & 2 closed |
| Disabled | Pins 2 & 3 closed |
REMOTE POWER FAILURE | |
| Setting | JP12 |
| » Transmit RPF tone | Pins 1 & 2 closed |
| Doesn’t transmit RPF tone | Pins 2 & 3 closed |
RTS/CTS DELAY | |||
| Setting | JP2/A | JP2/B | JP2/C |
| 0ms | Closed | Open | Open |
| » 9ms | Open | Closed | Open |
| 70ms | Open | Open | Closed |
TRANSMIT IMPEDANCE | |
| Setting | JP5 |
| » 135omhs | Pins 1 & 2 closed |
| Low | Pins 2 & 3 closed |
TRANSMIT LEVEL | |
| Setting | JP4 |
| » 0dBm | Pins 1 & 2 closed |
| -6dBm | Pins 2 & 3 closed |
V.54 DELAY | |
| Setting | JP11 |
| » 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 |