Comtech EF Data CRS-170 - Manual (Page 26)

CRS-170 1:1 Redundancy Switch Revision 1
Installation and Operations Manual MN/CRS170.IOM
28
4.1.1 M
ODEM
A C
ONTROL
C
ONNECTOR
The Modem A Control connector is a 9-pin D female interface located on the
modem side of the L-Band Switch Module. Refer to Table 2 for pin assignments.
Pins 2, 3, and 4 carry signals looped through the switch module from Modem B to
Modem A, while pins 6, 7, and 8 loop the same signals from Modem A through to
Modem B. The 12VDC input, which is diode OR’ed with the corresponding
12VDC input from modem B, powers the switch module.
Table 2. J3A - Modem A Control Connector Pin Assignments
Pin # Signal Function Signal Name Direction
1 Signal Ground Ground -
2 Modem B 232 Tx AUX_SER_TX_B Out
3 Modem B Online Indication ONLINE_OUT_B Out
4 Modem B Fault Indication /FAIL_OUT_B Out
5 Signal Ground Ground -
6 Modem A 232 Tx AUX_SER_TX_A In
7 Modem A Online Indication ONLINE_OUT_A In
8 Modem A Fault Indication /FAIL_OUT_A In
9 +12 VDC +12VDC In