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Algorithm for XML Checksum?


Hey there!
I was reading through the documentation for the XML Communication protocol, and noticed that there must be a checksum for the payload included in the wrapper, but couldn't see how this checksum is calculated.
For instance, is it a CRC32 checksum? Or is it an 8-bit two's complement checksum like the touchscreen communication?

Hi! Welcome to the forums. Without testing I would guess two's compliment, but that is only a guess. I can't test it at the moment, but could probably work on it tonight or tomorrow and get an answer for you.

Well so much for testing... I was getting replies from the xml service no matter what I had as the checksum. Even empty and non-numeric checksum values worked.

Thank you for the welcome! Admittedly I also did not test it yet, I was pseudo coding up a project and wondered what it was haha. Do you think I should code my project using 2's complement for now just to be safe? (i could likely easily change it later without much issue I imagine)
I'm also curious if the length will matter and what it's based on (length of the Bytes or length of the actual XML string), but I can probably figure that out pretty easily through some testing.
Thanks for your quick reply and help!

Sure thing! Length was the number of characters in the request string. Basically everything but the wrapper. Happy coding!

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