checksum 8 bit modulo 256

[Garyeh]

Hello All,

How do I calculate the 8 bit modulo 256 checksum?  See the example from the manual.

Example:

            To send the Set Temperature of 100.0 Deg. to controller.

            Fixed Decimal Set Temp is multiplied by 10 to prepare to send.

            Convert 1000d to hex which is 03e8

            Send:               (stx)001c000003e8b4(etx)

So..in the example the checksum is b4.

Thanks in advance.

Gary

[Todd_Lesher]

http://lavag.org/topic/15556-2s-complement-of-a-string/page__view__findpost__p__94063

[Darin.K · Accepted solution]

[Garyeh]

Darin,

Excellent! I had initially tried that but it didn't seem to work.

Thanks!

Gary