Encoder signal level is too low, faulted (incorrect shielding), or the cable breakage monitoring function has responded.After separately shutting down the supply voltage at the drive, for

-Use the original Siemens pre–assembled encoder cables (better screening)

– Check for sporadic interruptions (loose contact, e.g. when the drag cable is being moved)

– For toothed–wheel encoders, check the clearance between the toothed wheel and sensor

– Check the encoder, encoder cables and connectors between the motor and control module

– Check the screen connection at the front panel of the control module (top screw)

– Replace the encoder cables or the control module

– Exchange the encoder or motor

– If this fault was signaled without any significance, then it should either be acknowledged in the control or the drive and control should be powered–down together.

Check it out....

Regards,
Ekalavya