Comtech EF Data SDM-100A - Manual (Page 128)

Theory of Operation SDM-100A Satellite Modem
4–12 Rev. 0
4.3.4 Remote Interface Configuration
All modem functions can be remotely controlled and monitored via an RS-485 (or
optional RS-232-C) communications link. The 2- or 4-wire, half-duplex RS-485 interface
makes it possible to operate up to 255 modems and other units on a common
communications link. The RS-232-C interface is used to communicate with a single
modem.
The M&C must be hardware configured to one of the two interfaces:
• RS-485 configuration:
Install two jumpers (shunts) at RS-485 positions of JP10, and install one jumper
at the RS-485 position of JP4. For 2- or 4-wire operation, position jumpers at JP2
and JP3 to the designated positions.
• RS-232-C configuration:
Install two jumpers (shunts) at RS-232-C positions of JP10, and install one
jumper at the RS-232-C position of JP4. For 2- or 4-wire operation, position
jumpers at JP2 and JP3 to the designated positions.