Re: Reading data from energy meter using modbus protocol
I'd recommend that you start with something you have control over (in both directions).
1) Test using an RS232 to RS485 converter, and ModScan or something similar on your PC. Ensure that you can read the appropriate registers from the Power Meter using the baud rate, parity etc that you expect.
2) Testing using the same RS232 to RS485 converter and ModSim or something similar on your PC. Ensure that you can read the appropriate registers from your Computer (into the Arduino) using the baud rate, parity etc that you have configured on your Computer to match what the Power Meter was tested in 1) using.
Then it should be trivial... you know how to read the values from the Power Meter, and you know how to read values using the Arduino board. Therefore you know how to read the values from the Power Meter with the Arduino board.
I assume you already understand that Modbus Protocol <> RS485... if you're confused at what I'm suggesting here, then you probably need to read up more on what RS485 actually is, and why that is not the same as ModbusRTU.