RoyalTek RDR-3100 - Manual (Page 24)

RDR-3100 User Manual
8.3.2 GPS antenna detection output Message
This sentence contains the GPS antenna detector information which read from
GPS module and send to the CAN bus.
The protocol is illustrated as follows:
Item Field Description
1 $ Beginning of sentence
2 PSRF122 Message Header
1: antenna connected 3 GPS antenna status
0: antenna not connected
4 *CC<CR><LF> Check Sum and sentence termination delimiter.
The algorithm of checksum calculation is same
With the one to calculate NMEA checksum.
Example:
$PSRF 122,1*3B<CR><LF>
GPS antenna connected
Check sum= 0x3B.
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