Checksum calculation – Kistler-Morse KM STXPlus User Manual
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APPENDIX B: KISTLER-MORSE
®
PROTOCOL SERIAL COMMANDS
Table B-2. Definitions of Characters in Command Strings.
CHECKSUM CALCULATION
The 1-byte checksum is calculated by adding the hex values of all ASCII characters between the
start of message character ‘>’ or acknowledge character ‘A’ and the checksum character ’ss.’
Overflows from the addition are ignored.
Request
To request gross engineering units (such as weight) from an STXplus, the command is:
>aaWssr
If the STXplus’s address is ‘3’, the command is:
>03Wssr
Calculating the checksum ‘ss’ as the sum of the Hex values of all characters between ‘>’ and’ss’:
03W ASCII = 30 Hex + 33 Hex + 57 hex = BA Hex
‘0’ ‘3’ ‘W’
Therefore, the ASCII string transmitted to the STXplus is:
> 0 3 W B A CR
3E 30 33 57 42 41 0D Hex
B-4