Mapping list for modbus register


Thread Starter

Chris Brown

I am looking for a mapping list for modbus register 0 and on for a system with a default configuration . Does such a list exist.
What you've provided doesn't make much sense to me. Modbus mapping register? For what type of device? A PLC doesn't have any defaults, it's unconfigured out of the box. Other devices may have specific tables of what data is located where. But a PLC is blank out of the box.

Also, typically a modbus register address is at least 1 (ie. 40001 or 30001 are the first valid addresses in a Modicon PLC).


Manesh T. Varghese

Dear Chris,

As such there exists no mapping register for any PLC. It needs to be congigured in the PLC as per the configuring instructions in the supporiting software.
The only common things for any Modbus Mapping is that you need to specify
1.Line Charecteristics
2.Network /Node & Master/Slave specification
3.Addressing types and function codes
4.Crossreference table for Modbus register address and corresponding database elements of the PLC/DCS software.
5.Read/Write Commands.
Eeach system has its own configuration tools for configuring these basic things.

Manesh T. Varghese