Positive and negative hard limit alarm of CNC computer gong
Normally, this alarm will not occur. Operating machine tools before returning to zero may occur. Because the system does not have fixed mechanical coordinate system before returning to zero, it locates at will, and the soft limit is invalid, so it must return to zero before operating machine tools. Causes of positive and negative hard limit alarm for CNC computer gongs:
1. The contact of the travel switch is pressed and jammed.
2. The stroke switch is damaged.
3. Circuit breakage, short circuit and no signal source occur in the trip switch circuit.
4. Limiting block can not press the switch contact to the action position.
5. The input point of PLC is burnt out.
The positive and negative hard limit alarm Countermeasures of CNC computer gong:
1. Manual or handwheel shake off the safe position, or clean switch contacts;
2. Change the stroke switch.
3. Check whether there is a short circuit in the circuit of the stroke switch, and if there is a short circuit, it will be dealt with again. Check the signal source (+24V DC power supply);
4. Adjust the installation position of the stroke switch so that it can be pressed up to the action position by normal pressure.
5. Replace the input points on the I/O board, set parameters and modify the PLC program.