2 utility connector group, 1 j1 | alarm connector, db-15m – Comtech EF Data CDM-750 User Manual
Page 54
CDM-750 Advanced High-Speed Trunking Modem
Revision 2
Rear Panel Connections
MN-CDM750
3–8
3.2.2
Utility Connector Group
3.2.2.1 J1 | ALARM Connector, DB-15M
The 15‐pin Type ‘D’ male (DB‐15M) J1 | ALARM connector provides the unit
alarms interface.
The connector pinouts are as follows:
Pin # Name
Signal Function
Direction (I/O)
1 GND
Ground
Gnd
9 EXT-OFF
Ext Carrier Off, active low.
Capability to mute modem’s Tx IF (Low=Mute) (Has internal pull-up in the
Modem). Compatible with LVTTL or relay pull down.
I
2 AGC (NOT AVAILABLE) AGC Voltage (Rx signal level, 0 to 10 volts, monotonic)
O
10 N/C
No
Connection
–
3 RX-Q
Rx Q Channel (Constellation monitor)
O
11
RX-I
Rx I Channel (Constellation monitor)
O
4 UNIT-COM
Unit
Fault
I/O
12
UNIT-NO
Unit Fault (Energized, No Fault)
I/O
5 UNIT-NC
Unit Fault (De-energized, Faulted)
I/O
13 TX-COM
Tx
Traffic
I/O
6 TX-NO
Tx Traffic (Energized, No Fault)
I/O
14
TX-NC
Tx Traffic (De-energized, Faulted)
I/O
7 RX-COM
RX
Traffic
I/O
15
RX-NO
Rx Traffic (Energized, No Fault)
I/O
8 RX-NC
Rx Traffic (De-energized, Faulted)
I/O