Machine tools cannot return to zero point.

Reason:

1. The original switch contact got stuck and failed to operate.

2. The original point stopper cannot press the original point switch down to the switch activation position.

3. Rusty contact points due to water ingress from the original switch.

4. Original switch circuit disconnected or input signal source malfunction.

PLC input points have been burned out.

Countermeasures:

Clear jammed parts to ensure smooth movement of the actuating components, or replace the stroke switches; adjust the installation position of the stroke switches to allow the zero-point switch contacts to be easily pressed into the switch actuation position; replace the stroke switches and implement waterproofing measures; check for open or short circuits in the switch circuit, and verify the presence of a signal source (+24V DC power); replace the input points on the I/O board, set parameters, and modify the PLC program.

Machine Tool Positive and Negative Hard Limit Alarm

An alarm like this would typically not occur under normal circumstances. It may happen before the machine tool is reset to zero, as the system does not have a fixed mechanical coordinate system before zeroing, but is arbitrarily positioned, and the soft limit is ineffective. Therefore, it is necessary to reset the zero point before operating the machine tool.

Reason:

行程switch contacts were pressed and jammed (exceeded travel).

2. Trip switch failure.

3. The routing circuit encountered issues with open circuits, short circuits, and no signal source.

4. The limiting block cannot press down the switch contact to the action position.

5. PLC input points burned out.

Appropriate Countermeasures:

Manually or by handwheel, remove from the safety position or clean the switch contacts; replace the stroke switch and inspect the switch circuit for short circuits, and if found, reprocess. Check the signal source (+24V DC power); adjust the stroke switch installation position to ensure it can be properly pressed onto the switch contacts to the actuating position; replace the input points on the I/O board and configure the parameters, and modify the PLC program.