Comtech EF Data CDM-740 - Manual (Page 47)

CDM-740 Advanced Satellite Modem Revision 0
Rear Panel Connector Pinouts MN-CDM740
3–5
3.4.3 Remote Control Interface Connector, DB-9M
The Remote Control Interface is a 9-pin Type ‘D’ male connector. It is
intended for connection to an M&C computer or terminal device, and is user
selectable for either EIA-232 or EIA-485. Refer to Table 3-4 for pinouts.
Table 3-4. Remote Control Connector Pinouts
Pin # Description Direction
1 Ground –
2 EIA-232 Transmit Data Out
3 EIA-232 Receive Data In
4 Reserved - do not connect to this pin –
5 Ground –
6 EIA-485 Receive Data B * In
7 EIA-485 Receive Data A * In
8 EIA-485 Transmit Data B Out
9 EIA-485 Transmit Data A Out
* Use for 2-wire EIA-485 operation
3.4.4 EXT/INT REF Connector, BNC
The Ext/Int Ref connector is a BNC female connector. The signal supplied here
by the user is used for phase-locking the internal 10MHz reference oscillator, and
can be 1, 2, 5, 10 or 20 MHz. The impedance is matched for 50/75
Ω, and requires
a level in the range –6 to +10 dBm.
Connector Type Description Direction
BNC External Reference In/Out