Is NLP or STO faulty state? What about relay assigned to "no drive fault" will it signalize fault?

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What is the meaning of NLP and STO state of Altivar variable speed drive? What is the status of the Relay output assigned to "no drive fault", will it signalize the fault?

The NLP state represents "no-line power". If you supply 24V for the control circuit while power supply is missing. The drive can be configured, exchange data via HMI, over communication, etc. It is not a fault state though the drive will not accept the Run command.

The STO state (safe torque off state) represents the normal state (not a fault) with the safety function "safe torque off" activated. STO can normally occur during operation when the operator activates STO input for example.

To sum up, none of NLP or STO triggers the fault state, so the relay assigned to "no drive fault" will still signalize "no fault".