The Modbus RTU Slave Interface determines the file specification of the configuration file at startup by combining the file name MRTUSI_RP.CFG with the file path of the Project directory.
If the project has been created in the directory
C:\Program Files\GE Fanuc\Proficy CIMPLICITY\Projects\test\
Then the configuration file specification is:
C:\Program Files\GE Fanuc\Proficy CIMPLICITY\Projects\test\data\MRTUSI_RP.CFG.
Step 1. Edit the Modbus RTU Slave configuration file.