I have a ControlLogix system that has been running for awhile now. I need to read data from this controllogix via Modbus TCP. I can change the controllogix code as needed but cannot add any new modules. How can I read tag data via modbus tcp? From the modbus side of things I need to enter an address i.e. 40012 and have that correspond to a tag in the controllogix i.e. DataTag. I have been told this is possible but cannot find any examples and the person who told me about a system like that can't remember how it was done but states it was all through programming in the controllogix and no extra modules or converters etc were needed. So does anyone have any ideas? Thanks!