这个故障很常见，请准确描述在什么情况下出现的20005故障，具体可以查帮助文件
Cause
The driver of a physical device or the device itself has failed or is faulty.

If this alarm occurs, the cause of the error must be evaluated in the external device (drive or encoder).


0x0020h Encoder driver was not initialized during ramp-up

REMEDY
For reason 0x0020

Make sure that the user program does not reference a technology object containing an encoder (Axis, External Encoder) with an '_enableaxis' or '_enableexternalencoder' command while system variable 'sensordata.sensordata[n].state' is signaling invalid.