You can verify whether communication between the TOP main unit and the PLC is functioning properly by using the [Communication Diagnosis] button on the TOP device.

Navigate to the menu screen on the R product.

Go to the [Control Panel] - [PLC] menu, where you will find the [Communication Diagnosis] button at the bottom.

If a [Communication Success] message pops up, it means the cable and communication settings are correct, and communication is functioning normally.
If an [Error] message appears, communication is not working properly. In this case, please check the cable and communication settings again.