DMD20/20LBST Universal Satellite Modem
Rear Panel Interfaces
MN-DMD20-20LBST Revision 14
5–5
5.4.4 RX IF
The Receive IF Input Port is a 75-Ohm Female BNC Connector that is used for 70/140 MHz IF. If
the customer orders the 70/140 MHz IF, the Transmit IF Output Port is a 75-Ohm Female BNC
Connector.
5.4.5 RX L-Band IF
The Receive IF Input Port is a 50-Ohm SMA Female Connector that can be used for L-Band IF.
The IF Frequency can be programmed from 950 to 1750 MHz in 1 Hz Steps.
5.4.6 ALARM (J15)
The Alarm Port is a 15-Pin Female “D” Connector. The Alarm port utilizes contact closures to
identify the status of the modem. Front panel selections allow the user to select the utilization of
the contact closures. Refer to Table 5-2 for pinouts.
Pins 1 through 6 offers form C contacts for Major Alarm Status on the Modulator and
Demodulator. When the modem is configured for IBS Network Specification, pins 7-9 only
support the IBS Prompt Alarms and pins 10-12 only support IBS Service Alarms.
If the Network specification is configured for Closed Net, the contact closures for Prompt and
Service can be utilized to include the summary of all minor alarms or minor/major alarms. This
option can be enable via the BB Relays located in the General menu. The IBS Prompt menus
can include TX Minor Alarms or TX Minor Alarm and TX Major Alarms. The IBS Service Alarms
can include RX Minor Alarms or RX Minor Alarms and RX Major Alarms.
Additional support of the BaseBand relays includes status monitoring of the RTS Carrier. When
RTS carrier is enabled and Baseband relay configured for RTS Keyline, the Service alarms pins
10 thru 12 will monitor the status of the RTS signal.
Table 5-2. ALARM Port 15-Pin Female “D” Connector (J15)
Pin No.
Signal Name
Signal
Direction
1
Mod Fault
MF-C
No Direction
2
Mod Fault
MF-NC
No Direction
3
Mod Fault
MF-NO
No Direction
4
Demod Fault
DF-C
No Direction
5
Demod Fault
DF-NC
No Direction
6
Demod Fault
DF-NO
No Direction
7
Prompt
CEF-C
No Direction
8
Prompt
CEF-NC
No Direction
9
Prompt
CEF-NO
No Direction
10
Service
SP1-C
No Direction
11
Service
SP1-NC
No Direction
12
Service
SP2-NO
No Direction
13
No Connection
SP2-NC
No Direction
14
AGC Out
AGC
No Direction
15
Ground
GND
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Note 1:
Normally open, or Normally closed, conditions indicate a faulted state or off condition.