When I tried to open the COM port with the MU-4 Evaluation Program, the message 'Can't Open the Port. Please check the hardware.' appeared and the connection failed.

The message appears when the communication parameters do not match. Initialize the interface board to match the communication parameters of the Evaluation Program with the MU-4. How to initialize the MU-4:

  1. Turn on the power while pressing the initialize button (the reset switch).
  2. Turn off the power
  3. Turn on the power again.

Initialized communication parameter values: Baud rate = 19,200, Data bit length = 8, Stop bit = 1, Parity bit = None, Flow control = Hardware

In addition if mounting MU-4 on own board, the CTS, RTS, DTR and DSR pins must be used otherwise the evaluation program will not be able to establish interface. Please refer to the circuit diagram in the MU4-RS2IF operation guide.