If the encoder count changes 1 when connecting the 'COM' terminal and the 'A' terminal with the controller switched on (e.g. if the counter is 1000 to 1001 or 999).

There is a problem with encoder or encoder wiring, especially if the wiring is extended, and there is no change, there is a problem with the control device.

To view the encoder counter, press the number 4 button in the initial mode to display the encoder counter.

In case of photo sensor or loop sensor input.

If the LCD (liquid window) shows STOP MANU (AUTO) RD --- instead of L (loop sensor), S (photo sensor), and P (pressure sensor).
Check the photo sensor, roof sensor, and pressure sensor.
Photocensors are especially vulnerable to moisture or dust, so regular checks are required.
Also, the input display mode should be Inputs : . . . . . . . on the LCD.If the alpabet floats, check the switch input.