ICS ELECTRONICS 4863 Manual page 112

If Packet Protocol is enabled, messages must conform to the following
format:
STX Addr Message Characters.. ..ETX Checksum
Where
STX and ETX are ASCII characters
Addr is the 2363's address
Checksum is a 8 bit checksum created by exclusive ORing all of
the characters from the STX to the ETX character.
The 2363 responds to each valid packet with an ACK response packet if the
message was a query or with an acknowledgment response if the message
was not a query. The command acknowledgment packet contains the ESR
register value. e.g.
ACK Addr ESR Register Value ETX Checksum
ACK Addr Optional query response..ETX Checksum
A NAK packet with the following format is returned if the original
packet had a bad checksum or if there was a command problem.
NAK Addr ESR Register Value ETX Checksum
Some command-response examples are:
Message
*CLS
ACK 4 0
*xxx
NAK 4 32
*esr?
ACK 4 32
*idn?
ACK 4 ICS-..
Packet
02 34 2A 63 6C 73 03 63
06 34 30 03 01
02 34 2A 78 78 78 03 67
15 34 33 32 03 23
02 34 2A 65 73 72 3F 03 44
06 34 33 32 03 30
02 34 2A 69 64 6E 3F 03 43
06 34 49 43 53 20 45.....2E 32 32 03 08
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