Research Concepts RC2000C - Manual (Page 90)

82 RC2000C Az/El Tracking Antenna Controller Appendix E Communications Protocol
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Appendix E - RC2000C Communications Protocol
Revision History
1.22.92 - Original communications protocol for the RC2000A derived from the RC1000A sabusext.inc
file.
4.6.93 - Revised to document the new Auto Move to a target Az/El position command in the RC2000A
version 1.30 software.
1.2.95 - Revised to document the new Auto Move to a target polarization position command and the
new byte 32 function of the device status poll command reply in the RC2000A version 1.31 software.
3.21.95 - Revised for the RC2000A version 1.32 software which provided support for the high power
polarization option. The POL JAMMED and POL SENSOR alarm messages have been replaced with
the ANT POL alarm. The drive error status field of bytes 27 and 28 has been removed.
5.31.95 - Revised for the RC2000C version 1.00 inclined orbit satellite tracking software. Extra track
status information has been included in the device status poll reply. A track MISCELANEOUS
command has been included to set the frequency band for dual band satellites and to reset track errors.
11.6.95 - Revised for the RC2000C version 1.1x release. The only change in the comm protocol is the
reply to the Query Id command. The alarm codes that appear in this document have also been
corrected.
3.15.00 – References to Azim East and Azim West have been changed to AZIM CCW and AZIM CW
respectively.
OVERVIEW
The RC2000C command set conforms to the SA Bus protocol originally defined by Scientific Atlanta.
This file describes the commands used to implement the SA bus remote interface for the RC2000
antenna controller. See the SA bus specification included with RC2000 manual for a complete
description of the protocol.
RC 2000 BAUD RATE - ADDRESS SPECIFICATION
The baud rate and address must be set before communication with a host is possible. These quantities
can be specified in the CONFIG mode. The range of acceptable addresses is 49 to 111 (decimal). The
possible baud rate values are 300, 600, 1200, 2400, 4800, or 9600. The usual SA Bus baud rate is
9600. For completeness, the transmission parameters are repeated here: 7 data bits, even parity, 1
stop bit.
RC 2000 ONLINE/OFFLINE
To enable remote mode on the RC2000, the internal remote$mode$enable$flag must be set. This flag
is set at the 'REMOTE MODE ENABLE' prompt in CONFIG mode. When this flag is set, remote mode
can be entered in two ways. One way REMOTE mode can be activated is by depressing the mode
button. REMOTE mode can be found just after AUTO mode. The second way REMOTE mode can be
activated is when a valid command arrives via the serial port. Certain commands can be processed by
TRACK mode.
If the remote$mode$enable$flag is FALSE and a valid command arrives via the serial port, the offline
reply is sent to the host. Here is the format of the offline reply...
byte 0: ACK
byte 1: A where A is the RC2000 address
byte 2: 'CC' the command code of the message which triggered this reply.