CIMPLICITY provides a sample Modbus master test program. The test program generates Modbus requests and displays the received responses. To test communications with the Modbus RTU Slave Interface, two serial ports are required - one port for the test program, and the other port for the Modbus RTU Slave Interface.
For more information regarding the test program, refer to the CIMPLICITY Device Communications Manual (GFK1181G), Modbus RTU Communications, Validating Modbus RTU Communications.
About Modbus RTU Slave Communications.