1. Work directly after the power on without return to zero
Especially in the case of old equipment or machines whose parameters have been changed, when the machine is turned on and cut to manual or automatic mode, the system realizes that the axis has not returned to zero, and immediately gives you a 300 alarm. This belongs to the "rules are not finished”, back to zero, basically immediately disappear.
2. Dismantled the motor, unplugged the encoder cable
As long as you have done the following things:
- Dismantled the servo motor
- Unplugged the encoder
- Moved the cable, connected to the line
- You've serviced something in the electrical cabinet.
The APC data may not match. We have encountered a lot of Z-axis cases, the motor is repaired and installed back, the first time you turn on the machine must report 300, in fact, the encoder is not bad, but the synchronization relationship is broken.
3. APC battery voltage is low
This is a point that many people tend to ignore. Absolute encoder is relying on the battery to maintain the position memory. When the battery voltage falls to a critical value, the system may not have reported 306, 307 those battery alarm, but it has begun to lose position information. The result: as soon as the machine is turned on, it gives you a 300 alarm straight away.
If you find that every time you turn off the motor and turn it on again, it will report 300, then 80% is a battery problem. Here is a key reminder: the battery must be replaced in the power state, otherwise the position data will be completely lost.
4. Encoder signal instability
Some machine tool electrical cabinet environment is poor, vibration, plug oxidation, wiring harness has dark cracks. Once the signal transmission is not stable, the system can not confirm the absolute position, it will not directly say "communication failure”, but first let you return to zero. So sometimes 300 alarm is a "superficial phenomenon”, but the bottom is communication instability.
