I am trying to read Modbus RTU data of an energy meter through com port of 750-8208.
COM port is 0.
But I am not receiving any response from the slave device. i have attached pictures for reference.
Hi,
some points to check
- is the com port in WBM unassigned
- com port settings correct (baudrate, parity, etc.)
- wires swapped
- error code of zz_MBCFG_MASTER in generated code MBCFG_ModbusSlave
Is it correct, that you want to read 50 consecutive reals (=100 registers) at once? Check if there is a limit of consecutive registers in a row for the smartmeter. Best ist to start with 1 or 2 registers for testing.
Do you have a task declared for your main program? The PLC_PRG will only be executed as free running task if no task is declared. The modbus configurator puts the modbus code in a seperate task, so that you have to declare also one for your main program.
Make sure you have terminal resistors at both ends of the line!
You can use the wago 750-960 profibus connector on the PLC port.