Research Concepts RC2500 User Manual

Page 85

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78

RC2500 Antenna Controller

Appendix E

RC2500 Comm Protocol

Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas • 66218-9680 • USA

www.researchconcepts.com

byte 4

checksum

The reply to this query will consist of 11 bytes ...

byte 0

ACK

byte 1

A

where A is the RC2500 address

byte 2

30h

the device type query command code

bytes 3-6:

'XXXX'

where the value of 'XXXX' depends on the controller and mount
type:
2500 for non inclined orbit tracking controllers
25CA for inclined orbit tracking controllers designed for elevation
over azimuth mounts
25CP for inclined orbit satellite tracking controllers designed for
polar mounts with power declination or power latitude angle
adjust
25CE for inclined orbit tracking controllers designed for azimuth
over elevation type mounts.

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 RC2500 address

byte 2

31h

the status poll query command code

byte 3

ETX

byte 4

checksum

The response to this command will consist of 52 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 RC2500 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

not used

reserved for future use, currently initialized to 0100$0000b.

byte 14-19

azimuth position

This field will contain the formatted azimuth position 0.00

to 359.99. If the azimuth resolver to digital converter detects an
error this field will contain ‘******’.

byte 20-25

elevation position

The field will contain the formatted elevation position, ‘-

99.99’ to ‘260.00’. If the elevation resolver to digital converter
detects an error this field will contain ‘******’.

byte 26-30

polarization position

This field will contain the formatted polarization position

‘-99.9’ to ‘260.0’. If the antenna is not equipped with a rotating
feed or if the polarization resolver to digital converter detects an
error this field will contain ‘*****’.

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