RESEARCH CONCEPTS RC2000A DUAL AXIS Instructions Manual page 72

72 RC2000A Dual Axis Antenna Controller
New Commands
The following commands are supported in this version of the software ...
Reflect Display – transfers the contents of the controller's LCD to the host PC.
Config Read/Write Commands – Download/upload CONFIG mode data.
Sat Data Read/Write Commands – Download/upload non-volatile satellite data.
User Auto Move – Supports auto moves to target az/el/pol target positions.
Bugs Fixed
Query ID Command – in past versions of the software, the command field of the reply to this
command did not contain the correct command code.
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 RS-422 Serial Interface Addendum 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. 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$flag must be set. This
flag is set at the 'Remote Mode Enable' prompt in CONFIG mode. When this flag is set, REMOTE
mode can be entered in two ways. One way REMOTE mode can be activated by depressing the mode
button. REMOTE mode can be found just after AUTO mode. The second way REMOTE mode can be
activated is if certain serial commands are received by the serial port. Currently the Miscellaneous
Keystuff, Display Reflect, and Device Status Poll commands can be processed with transferring control
to REMOTE mode.
If the remote$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:
byte 1:
byte 2:
byte 3:
byte 4:
byte 5:
RC2000 UNRECOGNIZED COMMANDS - NAK REPLY
If an unrecognized command arrives (one whose command code is either unknown or whose length is
not compatible with the given command code, but which has the correct address and checksum), a
NAK reply is sent to the host. The format of the NAK reply is ...
byte 0:
Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas • 66218-9680 • USA
ACK
A where A is the RC2000 address
'CC' the command code of the message which triggered this reply.
'F' ASCII 'F', for offline.
ETX
checksum The checksum character is simply the bit-by-bit exclusive OR
of all characters in the message starting with the STX
character through the ETX character.
NAK
Appendix E Communications Protocol
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