There are many reasons why modbus might not be modbus. First, you don't have to implement all the functions (read coil, read register, write register, etc.) in order to claim modbus capability, this happen with both masters and slaves. Second, there is no separate address space for real numbers, so they get mixed in with the 16 bit integer registers with varying word order. There are others, too, but this is not a rant about strengths and weaknesses of modbus, the point is that using Modscan32 is a really good idea because it is the de-facto standard Modbus Master, when you tell someone you have results with that tool, it's something they can reproduce.
