Modbus Error: [Input/Output] No Response received from the remote unit

Question

I\' trying to connect from my Mac laptop to a Modbus device (MR-SI4) using a serial connection using a USB RS485 converter that gets \"mounted\" to /dev/cu.SLAB_USBtoU

Answer 1

Check this Stack_post.

You can handle the error:

if not result.isError():
    '''isError() method implemented in pymodbus 1.4.0 and above'''

    print(result.registers)  # Note.

else:
    # Handle Error.
    print('Unable to read or there is the connection problem.')

---

[NOTE]:

• In many cases, RTU parity is None: parity='N'
• Make sure from root permission on your serial port (/dev/cu.SLAB_USBtoUART).