PAVONE DAT 500 - Communication Error Handling; CRC Communication Control; Received Data Error Handling

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CONTROLS FORMAT DESCRIPTION:
The double quotes enclose constant characters (observe upper and lower case); the <and> symbols
contain variable numeric fields.
REQUEST FOR THE NET AND GROSS WEIGHT AND CURRENT PEAK
Master: <Addr> “N” EOT
DAT 500: “N” <Addr> <status> <net> <gross> <peak> ETX <chksum> EOT
CHANGE IN GROSS WEIGHT
Master: <Addr> “C” “L” EOT
DAT 500: <Addr> “C” “L” ACK EOT
CHANGE IN NET WEIGHT
Master: <Addr> “C” “N” EOT
DAT 500: <Addr> “C” “N” ACK EOT
COMMAND OF RESET OR AUTOMATIC CALIBRATION OR PEAK RESET
Master: <Addr> “A” “A” EOT
DAT 500: <Addr> “A” “A” ACK EOT
PROGRAMMING TWO WEIGHT SETPOINS
Master: <Addr> “S” <s1> <s2> ETX <csum> EOT
DAT 500: <Addr> “S” ACK EOT
REQUESTING FOR THE PROGRAMMED SETPOINT
Master: <Addr> “R” EOT
DAT 500: <Addr> “R” <s1> <s2> ETX <csum> EOT
STORING THE WEIGHT Setpoint IN A PERMANENT MANNER
Master: <Addr> “M” EOT
DAT 500: <Addr> “M” ACK EOT
In the case of communication error or otherwise unrecognized command from DAT 500, it will respond
with the following string:
DAT 500: <Addr> NAK EOT
FIELDS DECRIPTION
The double quotes enclose constant characters (observe upper and lower case); the <and> symbols
contain variable numeric fields.
<addr> = Serial communication address of the instrument; it is the ASCII character obtained by adding
80h to the number of address (i.e. address 1: <Addr> = 80h + 01h = 81h).
<csum> = checksum of the string data. It is calculated by performing the exclusive OR (XOR) of all cha-
racters from <Addr> to ETX excluded the latter; the result of the XOR is decomposed into 2 characters
by considering separately the upper 4 bits (first character) and lower 4 bits (second character); the
2 characters obtained are then ASCII encoded (example: XOR = 5Dh; <csum> = “5Dh” namely 35h
and 44h).
ETX (end of text) = 0x03h,
EOT (end of transmission) = 0x04h,
ACK (acknowledgment) = 0x06h,
NAK (No acknowledgment) = 0x15h.