Hi,
I must say that I found the Mach3 Mobus plugin quite confusing and still there are details which are still obscure.
I have done a little bit of work with the Mach4 Modbus plugin and while I struggled to start with I found it to be much easier
and complete than the Mach3 plugin. In particular in Mach4 you set up registers in the register plugin with names and
descriptions to make it human readable. The Modbus plugin has the means of concatenating the registers to form a
block.
The registers can be written to and read by Mach4 PLC, in similar manner to Mach3 Brains but they can also be written/read
by macros or any other Lua module within Mach4, very very much more flexible and easier to understand.
Would commend you download Mach4, run the Sim(ulator) plugin and play with the Modbus and Register plugins, light years
ahead of Mach3 IMHO.
Craig