I’ve been involved in working with various industrial communication networks for the past twenty years or so. One of the protocols I deal with is Modbus RTU. When interfacing with 3rd party devices, I know that the register addresses have to be incremented by one to be properly transmitted. For example, if I want to a read a register at 40100, I must set the register address to 40101 and it works just fine. If I data capture the actual transmitted register address, it is 40100. I’ve been to the Modbus web sites, and they mention this also, but they do not give an explanation. I’m just curious why the address decrements by one. Does anybody know?