Can any one please explain,how to map modbus registers to sensors & switches.(to analog and digital I/O's). I need to read the output of sensors by reading mapped registers.How can we do this?

 

The only answer possible is locate and read the manual published by the maker of the device or sensors.

Modbus does not include any standard 'mapping'. Modbus just says the device has a collection words of data which you can read or write.

The meaning is assigned by each manufacture, and they all do it differently.