Maintenance method of Siemens CNC system

If the monitoring light blinks at 1hz, the eprom is faulty. If the flashing frequency is 2hz, the plc is faulty. If it flashes at a frequency of 4hz, it will keep the battery alarm, indicating that the voltage is insufficient. Indicates that the interface board 03731 of the control panel is faulty or the crt is faulty.

1) There is no basic screen display after the power is turned on


(a) There is no monitor light display on circuit board No. 03840


(b) The monitoring light on circuit board No. 03840 is on


①The monitor light is flickering. If the monitoring light flashes at a frequency of 1hz, the eprom is faulty; if the flashing frequency is 2hz, the plc is faulty; if it flashes at 4hz, the battery will keep alarming, indicating that the voltage is insufficient.

②Monitoring lights are off on the left and on on the right. Indicates that the interface board 03731 of the control panel is faulty or the crt is faulty.

③The monitoring light is always on. The usual reasons for this kind of failure are: cpu failure; eprom failure; system bus (ie backplane) failure, incorrect settings on the circuit board, wrong machine data, and circuit boards (such as memory boards, coupling boards, The hardware of the measurement board) is faulty.

2) Chaos displayed on crt


(a) Keep the voltage of the battery (lithium battery) too low. At this time, the alarm No. 711 can generally be displayed.

(b) The storage area has become cluttered because the power strip or storage has been unplugged. This is a kind of soft fault, as long as the cnc internal program is cleared and re-entered, the fault can be eliminated.

(c) The hardware failure on the power supply board or the memory board causes the program display to be confused.

(d) If No. 513 alarm is displayed on the crt, it means that the capacity of the memory is not enough.

3) The program cannot be started in automatic mode


(a) In this case, No. 351 alarm is generated, indicating that after the cnc system is started, the machine tool has not been operated to return to the reference point.

(b) The system is on automatic hold.

(c) Prohibition of cycle start. Check the interface signal q64.3 between plc and nc.

4) Feed axis motion fault


(a) The feed axis cannot move. The reasons for this failure are:


①The operation method is wrong;


②The signal transmitted from PLC to NC is abnormal;


③ The position control board is faulty (such as 03350, 03325, 03315 board is faulty).

④ Alarm No. 22 occurs, which means that the position loop is not ready.

⑤ The measurement system is faulty. If No. 108, 118, 128, and 138 alarms occur, it is caused by the measurement sensor being too dirty. If 104, 114, 124, 134 alarms are generated, the position loop has a hardware failure.

⑥The motion axis is in the software limit state. It can be released by moving the machine axis in the opposite direction.

⑦ When alarms 101, 111, 121, and 131 occur, it means that the machine tool is in a mechanical clamping state.

(b) The motion of the feed axis is discontinuous.


(c) The feed shaft shakes.

① The speed loop and current loop parameters of the feed drive unit are not optimized, or the AC motor is out of phase or the speed measuring element is damaged, which can cause the feed shaft to tremble.

②The position control board of the cnc system is faulty.

③The friction force of the mechanism is too large.

④The number of CNC machine tools is wrong, and the exact setting of the relevant machine data is as follows.

(d) The feed axis is out of control.

① If there are 101, 111, 121, 131 alarms, please check the clamping.

② If there are 102, 112, 122, 132 alarms, it means that the command value is too high.

③The feed drive unit is faulty.

④The setting of CNC machine tool data is wrong, causing the position control loop to be positive feedback.

⑤ The polarity of the instruction line output from the cnc device to the drive unit is wrong.

(e) No. 103-133 alarms. This is a profile monitoring alarm. The speed loop parameters are not optimized or the kv coefficient is too large.

(f) No. 105-135 alarms. Caused by too much position drift. If the displacement exceeds 500mv, check the drift compensation parameters n230~n233.

5) Spindle failure


If the actual spindle speed exceeds the maximum speed of the selected gear, alarm No. 225 will be generated; if the monitoring of the spindle position loop fails, alarm No. 224 will occur.

6) v?24 serial interface alarm


(a) When no data is sent or received within 20 seconds:


①External equipment failure;


②The cable is wrong;


③03840 boardfailure.

(b) The perforated tape information cannot be entered, the reasons are:


①The key switch on the control panel is in the off position, so that the tape program cannot be input;


②If the data protection switch on board No. 0384 is not in the release position, the data tape cannot be input;


③ If the subroutines l80~l99 and l900~l999 cannot be input, it may be caused by the PLC and NC interface signal q64?3 being “1” (cycle prohibition).

(c) Rest bit error.

①The baud rate setting is wrong;


②The reading machine is faulty;


③The machine data is wrong.

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