Siemens Sinamics s120 Commissioning Manual page 380

Diagnostics
4.6 Troubleshooting for encoders
Cyclic acknowledgement
Acknowledgement using the encoder interface (Gn_STW.15)
The following responses are possible:
● The encoder is set to fault-free if a fault is no longer active. The fault bit in the encoder
interface is acknowledged. The evaluation modules indicate RDY LED = green after
acknowledgement.
This behavior is valid for all encoders connected to the encoder interface, irrespective of
the measurement system type (motor or direct).
● If the fault still exists, or if other faults exist, the acknowledgement is not successful – and
the highest priority fault (can be the same or another fault entry) is transferred via the
encoder interface.
The RDY LED on the evaluation modules is continuously red.
This behavior is valid for all encoders connected via the encoder interface, irrespective of
the measuring system type (motor or direct).
● The drive object is not detected via the encoder interface. Faults set in the drive object
remain, the drive does not even start with the encoder which in the meantime is fault-free.
The drive object must also be acknowledged via the drive interface (fault memory
RESET).
Acknowledgement using the drive interface (STW1.7 (cyclic) or p3981(acyclic))
The following responses are possible:
● If no more faults exist, the encoder is set to fault-free and the fault bit in the drive interface
is acknowledged. The evaluation modules indicate RDY LED = green.
Acknowledgement takes place on all encoders that are logically assigned to the drive.
● If the fault still exists, or other faults exist, then the acknowledgement is not successful;
the next, highest priority fault is transferred via the drive interface and also via the
encoder interface involved.
● The RDY LED on the evaluation modules is continuously red.
● The encoder interfaces of the assigned encoders are NOT reset by acknowledgement at
the drive interface; the set faults remain.
● The encoder interfaces must also be acknowledged via the corresponding encoder
control word Gn_STW.15.
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STARTER Commissioning Manual
Commissioning Manual, (IH1), 07/2016, 6SL3097-4AF00-0BP5