Research Concepts RC2000A User Manual

Page 69

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RC2000A Dual Axis Antenna Controller

Appendix E

Communications Protocol

69

byte 2 : 30h the device type query command
code

bytes 3-6: 'RC2K'

bytes 7,8: 'XX' where XX is the version number,
for example if the current
software version number were
4.31, XX would be '43'.
byte 9 : ETX
byte 10 : checksum */

/* DEVICE STATUS POLL COMMAND **

The SA Bus specification requires that command character 31h cause
a device to return its status information. The reply to this
command includes azimuth, elevation and polarization position,
current satellite name, as well as limit, alarm and drive status
information. The status poll command message consists of 5 bytes
and the format is;

byte 0 : STX
byte 1 : A where A is the RC2000 address

byte 2 : 31h the status poll query command
code
byte 3 : ETX
byte 4 : checksum

The response to this command will consist of 38 bytes, which will
be a combination of ascii and binary data fields. The binary data
will be placed in the lower nibble of a byte whose higher nibble
will be initialized to a value which will make the result an ascii
character. The idea with this response is to be able to reproduce
the information presented on the LCD to the user when manual mode
is active. The format of the response will be;


byte 0 : ACK
byte 1 : A where A is the RC2000 address

byte 2 : 31h the status poll query command
code

bytes 3-12 : sat_name This field will contain the
satellite name in upper case
letters. If the name does not
occupy the entire field the name
will be left justified and the
string will be padded with
blanks. If a satellite name is
not currently displayed, this
field will contain blanks.

byte 13: sat_name status - binary data

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