Comtech EF Data CSAT-6070 - Manual (Page 65)

Appendix A. REMOTE CONTROL
A.1 Introduction........................................ A-1
A.2 Basic Protocol ................................... A-2
A.3 Commands or Responses ................. A-6
A.1 I
NTRODUCTION
This document describes the protocol and message repertoire for remote monitor
and control of the CSAT Outdoor terminal.
The electrical interface is either an
EIA-
485 multi-drop bus (for the control of
many devices) or an
EIA-
232 connection (for the control of a single device), and
data is transmitted in asynchronous serial form, using ASCII characters. Control
and status information is transmitted in packets, of variable length, in accordance
with the structure and protocol defined in later sections.
A.1.1 EIA-485
The EIA-485 interface is provided at the 19-pin circular J5 connector. The
interface is a 4-wire EIA-485 interface using the pin out shown in the table below.
Since a half-duplex communication protocol is used, the +Tx and +Rx as well as
the –Tx and –Rx signals can be tied together at the user end to support a 2-wire
interface. The EIA-485 driver is only active during transmission and is tri-stated
when not is use.
Table A-1. EIA-485 Interface
Pin Signal Name I/O Notes
A EIA--485 +Rx Input CSAT Receive line
B EIA--485 –Rx Input CSAT Receive line complement
C EIA--485 +Tx Output CSAT Transmit line
D EIA--485 –Tx Output CSAT Transmit line complement
T Ground Passive
A.1.2 EIA-232
The EIA-232 interface is provided at the 19-pin circular J5 connector. The
interface provides the five signals shown in the table below. The CSAT only
requires three wires (TD, RD and Ground), the other two signal are provided for
A-1