Specifications

9. Troubleshooting and Fault Information

9-1

 Fault Indication From Panel

Common Problems and Solutions:

Ϩʳ POWER LED Indication

There is a Power indication LED on the front of the MPU unit. When power is on, the POWER LED (Green) will light up.

If the MPU unit LED does not light up when power is on, please remove the +24V wire and recheck the LED. If the LED

is now ON, it means the DC power supply is overloaded and cannot be used. Please use another DC24V source.

If the POWER LED still does not light up when the power is on after the above corrective actions, the PLC should be

sent back to the dealer or the distributor whom you purchased the product from.

Ϩʳ PLC RUN LED

When PLC is operating, the RUN LED will light up. Users can use an HPP or the Ladder Diagram to enter commands of

RUN and STOP.

Ϩʳ ERROR LED

The LED will flash if the program sent to the PLC is incorrect or too large. The user can check both the error codes

saved in the MPU data register D1004 and the fault codes of this chapter to correct the programs. Then, send the

corrective programs back to the MPU unit again.

If the connections between the PLC are failed and the LED will flash rapidly, this indicates the DC24V power supply is

down and please check for possible DC24V overload.

The LED will be steady if the program loop execution time is over the preset time (D1000 preset value), check the

programs or the WDT (Watch Dog Timer). When the LED lights up, switch the power ON and OFF to see if the RUN

LED is off. If not, please check if there is any noise interference or any foreign object in the PLC.

Ϩʳ Input point Indication LED

Input point ON/OFF status can be seen from the LED lights, which could also be retrieved from the HPP device

monitoring function for the monitoring purpose. Once the input point ON/OFF status is valid, the indicator will be ON.

Therefore, if errors are detected, utilize HPP, the indicator and the input signal circuit to check whether everything is

normal. Special care should be taken with those electronic switches with great current leakage, for it might result in

unexpected motions in the input point.