CONTROL-
1500B Single Axis Antenna Controller Appendix E Communications Protocol
72
CONTROL-
1500 ONLINE/OFFLINE
To enable remote mode on the RC1500, the internal remote$mode$enable$flag must be set.
This flag is set at the 'REMOTE MODE ENABLE' prompt in CONFIG mode. When this flag is
set, remote mode can be entered in two ways. One way REMOTE mode can be activated by
depressing the mode button. REMOTE mode can be found just after AUTO mode. The
second way REMOTE mode can be activated is when a valid command arrives via the serial
port. Certain commands can be processed by TRACK mode.
If the remote$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
CONTROL-
1500 address
byte 2:
'CC'
the command code of the message which triggered this reply.
byte 3:
'F'
Ascii 'F', for offline.
byte 4:
ETX
byte 5:
'chksum'
the 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.
RC1500 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:
NAK
byte 1: A where A is the
CONTROL-
1500 address
byte 2:
'CC'
the command code of the unrecognized message.
byte 3:
ETX
byte 4:
checksum
DEVICE TYPE QUERY COMMAND
The SA Bus specifications require that command character 30h must trigger the return of the
six-character device type string. The message format for this query will be ...
byte 0:
STX
byte 1: A where A is the
CONTROL-
1500 address
byte 2:
30h
30 hex - the device type query command code
byte 3:
ETX
byte 4:
checksum
The reply to this query will consist of 11 bytes …
byte 0:
ACK
byte 1: A where A is the
CONTROL-
1500 address
byte 2:
30h
the device type query command code
bytes 3-8:
'15_xxx'
where xxx is the version number, for example if the current software
version number were 4.31, XX would be '431'.
byte 9:
ETX
byte 10:
checksum
DEVICE STATUS POLL COMMAND
DAWNco • 3340 S. Lapeer Rd • Orion, MI 48359-1320 • Ph (248) 391-9200 • Fax (248) 391-9207 • [email protected]
