I intend to create a modbus slave, and it will only consist of a few readable registers. The hard question seem to be: How can the client identify my registers? Can I write some kind of file that can be loaded into the client? Is there any standard for this?

If I have understood this the right way, there is some form of identification files when dealing with i.e. profibus, but I have not found them for modbus.

Any information would be helpful, even a good term to google

 

Assign the data to 4xxxx registers. publish the assignments on paper. its as simple as that.

 

Modbus has no equivalent to a GSD file. Just list the registers in the documentation and count your blessings. Yours is one of the very few posts here where the words "GSD file" are not preceded by the words "I can't find the".

The user has to read the manual or data sheet anyway in order to see what the thing does. There's no need to make things more complicated than they have to be.