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Electrical Interfaces
5.4.5 ALARM (J5)
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 (J5).
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 5-4.
The pin definitions for J5 are shown in Table 5-5.
Note: The NC and NO (Normally Closed and Normally Open) nomenclature applies to
non-energized relays.
5.4.6 TX IF MON (J6)
The Transmit IF Monitor Port (J6) is used for injecting an external reference frequency into the
modem. The DMD2401 LB/ST Master Oscillator is locked to this source. All internally
generated frequencies within the modem will attain the stability of the applied external reference.
The external reference must meet the following parameters:
Frequency:
Amplitude:
Type:
Stability:
5.4.7 REF MONITOR 10 MHz (J7)
The Reference Monitor Port (J7) is used for injecting an external reference frequency into the
modem. The DMD2401 LB/ST Master Oscillator is locked to this source. All internally
generated frequencies within the modem will attain the stability of the applied external reference.
The external reference must meet the following parameters:
Frequency:
Amplitude:
Type:
Sinewave or Squarewave
5.4.8 CLOCK (J8)
The External Clock Port (J8) is used for injecting an external data clock into the modem. The
data symbol clocks may then be selected to be locked to this source. The external clock must
meet the following requirements:
Frequency:
Amplitude:
Type:
5.4.9 ESC ALARMS (J11)
The ESC Alarm Interface Port (J11) is the ESC Alarm Connector. It is a 25-Pin Female "D"
Connector. Refer to Table 5-11 for connector pinouts.
5-14
DMD2401 LB/ST L-Band Satellite Modem and ODU Driver
10 MHz, 9 MHz, 5 MHz, 2.048 MHz or 1.024 MHz.
0.2 Vp-p to 5 Vp-p
Sinewave or Squarewave
-7
1 x 10
or Better
10 MHz, 9 MHz, 5 MHz, 2.048 MHz or 1.024 MHz.
0.2 Vp-p to 5 Vp-p
9600 Hz to 2.048 MHz
0.2 Vp-p to 5 Vp-p
Sinewave or Squarewave
TM075 – Rev. 1.3
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