[checksum rs485 specific protocol]

thanks bob, then it also occurred to me, I did the function.

it works.

[checksum rs485 specific protocol]

Hi everyone, i'm new here, i'm working with plc, but i have unitronics usp-104-b10 on my desk up to now.
unilogic version: 1.28.34

  I need to solve crc checkum rs485 specific protocol of one noname thermostat. I tried it through message composer but it failed.
Thermostat works, I tested it with com debug, connection is ok.

Checksum definition:
checksum = (header + command + id1 + id1 + data0 + data1 + data2 + data3) and FF xor 3C
 

example: # H30 = (# H0B + # H00 + # H01 + # H00 + # H00 + # H00 + # H00 + # H00) & #HFF xor # H3C

  it should look like this: txBuffer = 0B 00 01 00 00 00 00 00 30

do you have any idea how to solve it?