We have plant data that exchages data with another system. We have been doing this for years via Modbus RS 232. He is the master and I am the slave. He is replacing his master device. The problem is our data does not match-up. When he tries to poll 100 in one of my registers he gets 97. the same thing happens when he tries to write 100. I get 97. There are no comm errors. Transmission looks good. The only thing I can tnink of is he has an error converting to or from a floating point number.