Siemens S7-200smart PLC MODBUS RTU Communication Case Study

1. TaskThe S7-200smart PLC reads the weight data from the weighing sensor via MODBUS-RTU communication.2. Device Model DataS7-200smart PLC:SR60 3. Introduction to MODBUS Master Station Commands4. Commands1. MODBUS Master Station Initialization Command2. Polling Method to Read Weight Value and Decimal PlacesUse the completion flag M10.0 of the initialization program and the completion flag M10.2 of the second MSG program to start the first MSG program, and use the completion flag M10.1 of the first MSG program to start the second MSG program.3. Data Parsing3. Compilation(1) During compilation, memory allocation must be performed; otherwise, an error will occur, as shown in the figure below(2) Allocate memory and compile4. Program Download and Check Program Running Results via Status Icons