Comtech EF Data DMD2401/DMD2401L - Manual (Page 142)

DMD2401/DMD2401L/DMD2401 IBS/IDR Satellite Modem Electrical Interfaces
TM065 - Rev. 3.3 5-3
Table 5-2. RS-232 Terminal Port – 9-Pin Female “D” Connector (J5)
Pin Number Signal Description Direction
2 TxD Transmit Data Input
3 RxD Receive Data Output
5 GND Ground –
5.3.6 ALARM (J6)
The modem has two Form-C Dry Contact Alarm Relays onboard and an Alarm Connector located
on the rear panel, the 9-pin male “D” sub connector (J6).
The two relays are designated Modulator Alarm and Demodulator Alarm. Non-Alarm is defined as
the powered state of the relay. Thus, if there is a Modulator Alarm and/or Demodulator Alarm, the
pins will be connected as shown in Table 5-3:
Table 5-3. Alarm Relays
Alarm No Alarm
Modulator
Pins 2 and 3 Shorted Pins 1 and 2 Shorted
Demodulator
Pins 8 and 9 Shorted Pin 7 and 8 Shorted
The pin definitions for J6 are shown in Table 5-4 below.
Note: The NC and NO (Normally Closed and Normally Open) nomenclature applies to non-
energized relays.
Table 5-4. Alarm Connector Pin Assignment (J6)
J6 Pin
Number
Connection
1 Mod Alarm Relay A NO on Alarm
2 Mod Alarm Relay A Common
3 Mod Alarm Relay A NC on Alarm
4
5 AGC Voltage Output
6 GND
7 Demod Alarm Relay B NO on Alarm
8 Demod Alarm Relay B Common
9 Demod Alarm Relay B NC on Alarm