I connect the OA-OB-OZ encoder outputs of the Servo Drive (ASDA-A2, B2, A3, B3) directly to the compact PLC inputs to get feedback from the servo system. However, it does not work. What am I supposed to do?

1–2 minutes

The encoder signal outputs of Delta Electronics Servo Drives have a 5VDC level, which is not proper to trigger the digital inputs of a basic compact PLC that need to be triggered with 24VDC.

Also, the working principle of the encoder output signals is the Line Driver. However, most controllers have the Open-Collector encoder inputs.

The diagram below explains a universal connection can be established between a line driver signal source and an open-collector encoder signal receiver.