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from the Forum department...
Do you recognize this error checking?
The packet is:
f0 58 02 00 4c 29 59 64
Where 0xf0 is a header byte indicating this packet is destined for the Host, 0x58 is an opcode, 0x20 0x00 means two data bytes to follow and the two data bytes are 0x4c 0x29. The error checking field bytes are 0x59 0x64. Do you recognize the error checking method used here?
f0 58 02 00 4c 29 59 64
Where 0xf0 is a header byte indicating this packet is destined for the Host, 0x58 is an opcode, 0x20 0x00 means two data bytes to follow and the two data bytes are 0x4c 0x29. The error checking field bytes are 0x59 0x64. Do you recognize the error checking method used here?
Are you sure the last byte is 64? There is a nice checksum calculator at http://www.lammertbies.nl/comm/info/crc-calculation.html? . There you can see that f0 58 02 00 4c 29 (ascii) gets 59 C4 for Xmodem checksum. I know close only counts in horse shoes and hand grenades, but C looks a lot like 6.
Eric
www.icpdas-usa.com
Eric
www.icpdas-usa.com
Yes it is a 0x64, here are a few more from the same com link.
f0 01 00 02 00 01 01 7e 9a
f0 15 00 00 00 97 aa
f0 16 00 00 00 9b ab
I am not including any Host to Slave messages because they are too long, it is a communication link between an RTU and its LCD display.
f0 01 00 02 00 01 01 7e 9a
f0 15 00 00 00 97 aa
f0 16 00 00 00 9b ab
I am not including any Host to Slave messages because they are too long, it is a communication link between an RTU and its LCD display.
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