Because of the numerical control system in modern higher reliability, CNC system itself, but most fault and failure is caused by the system itself. The system mainly refers to the due to external fault detection switch, hydraulic components and pneumatic components and electric actuators, mechanical device and problems.
CNC equipment malfunction can be divided into the external external hardware and software malfunction caused by damage to the hard fault. Soft failure due to operate and adjust refers to the improper handling, such failure occurs in the early or equipment used equipment use personnel adjustment period. For CNC system, another is the place for servo unit faults. Because each axis movement by servo unit control servo motor drive the ball screw. Use rotation speed feedback, make encoder grating as position feedback ruler. In place of the fault for rotary encoder and servo driver module of the unit. Also have individual is due to power caused by the system. Especially for those who take the computer disk save data system.

Example: a CNC lathe, just put into use in power system after the restart, must want to return to the point of reference. When manually will not interfere with each axis moved outside again after each axis, return reference points. Otherwise, the likelihood of the crash. Therefore, day after processing, it is best to move to the axis machine safe place. This operation or after powrefailure again won't appear problem.
External hardware failure is caused by the operation of the common faults control repair. Generally is due to the detection switch, hydraulic system, pneumatic system, electrical components, machinery equipment caused problems. This kind of fault alarm information searching through some failure. In general terms of nc system are fault diagnosis function or information alarm. The maintenance personnel narrow scope of diagnosis information. While some fault has alarm information display, but it can't reflect the real reason. Fault When the alarm information and fault phenomena to analyze and solve.
Also some fault fault alarm information, not only cannot fulfill the action, would then according to the maintenance experience, pressure machine and working principle of PLC operation condition for analysis and judgment.

For CNC repair, important is to find out the problem. Especially CNC external fault. Sometimes the diagnosis process is more complex, but once discovered, solve problem arose relatively simple. External fault diagnosis should follow two principles. First to mastering the working principle and action machine. Next, want to use PLC ladder diagram. NC system status display monitor PLC programmer or machine operation, the general principles as follow above, careful, general control fault will be promptly eliminate.
This article reprinted http://www.dgybl.com from (the),