Comtech EF Data SMS-758 - Manual (Page 145)

MN/SMS758 Rev. 3 B–1
Appendix B.
REMOTE CONTROL OPERATION:
INDEPENDENT MOD/DEMOD
This appendix defines the protocol and command structure for remote control and status
monitoring of the EFData SMS-758 switch.
•
Firmware number: FW/0713-36L
•
Software version: 6.1.2
B.1 General
Remote controls and status information are transferred via an RS-485 (optional RS-232C)
serial communications link. For RS-232C communication, switch SP1-5 on the M&C
module must be turned ON.
Commands and data are transferred on the remote control communications link as
US ASCII-encoded character strings.
The remote communications link is operated in a half-duplex mode. Communications on
the remote link are initiated by a remote controller or terminal.
The switch never transmits data on the link unless it is commanded to do so.
B.2 Message Structure
The ASCII character format used requires 11 bits/character:
•
1 start bit
•
7 information bits
•
1 parity bit (odd/even)
•
2 stop bits
Messages on the remote link fall into the categories of commands and responses.
Commands are messages which are transmitted to a modem protection switch, while
responses are messages returned by a modem protection switch in response to a command.