What it means
A07978 reports that the Essential Service Mode (ESM) has been activated on the drive and is waiting for the end of the motor data identification. The drive only enters the ESM mode once the motor has been completely commissioned: the motor data identification routine is performed at the next switch-on command, and after it the ESM mode becomes active. Depending on how the drive is configured, the same condition can also be issued with no reaction (N). The alarm itself does not trip the drive and needs no acknowledgement.
Why it appears
- The ESM mode has been activated while the motor data identification routine is also activated — the ESM mode cannot take effect until that identification is finished.
- The motor must have been completely commissioned before the ESM mode becomes active.
- The motor data identification routine runs at the next switch-on command; only then does the ESM mode become active.
What to check
- Take no corrective action: the manual states that a remedy is not necessary for this alarm.
- Give the next switch-on command so the pending motor data identification routine can run. The alarm is withdrawn automatically once the identification has been successfully completed.
- Alternatively, the alarm is withdrawn for the setting p1900 = 0 (motor data identification and rotating measurement).
Parameters the manual names
- p1900 (Motor data identification and rotating measurement / MotID and rot meas): the setting p1900 = 0 is one of the two conditions under which this alarm is withdrawn automatically.
- p1910 (Valve offset calibration standstill activation / Valv_off_cal act): the parameter the manual's note points to for the ESM mode; no setting on it is needed to clear this alarm.
Acknowledging and restarting
No acknowledgement is required. The alarm is withdrawn automatically, either after the motor data identification has been successfully completed or as soon as p1900 is set to 0. The identification itself starts with the next switch-on command, and once it finishes the ESM mode becomes active — the alarm then disappears without any operator action.
The same on every family
Every manual that describes A07978 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | Error in the parameterization / configuration / commissioning procedure (18) | None | SINAMICS S120, S150 List Manual · p. 2899 |
The drives this code lives on
A07978 is described for S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does SINAMICS alarm A07978 mean?
The ESM mode (Essential Service Mode) has been activated and is waiting for the end of the motor data identification. The motor must be completely commissioned before the ESM mode becomes active.
How do I clear alarm A07978?
You normally do nothing: the alarm is withdrawn automatically once the motor data identification has been successfully completed. Alternatively, the setting p1900 = 0 also withdraws it.
Does A07978 need to be acknowledged?
No. The alarm causes no reaction and requires no acknowledgement; it disappears by itself after the identification or when p1900 = 0 is set.
What is ESM on a SINAMICS drive?
ESM stands for Essential Service Mode. A07978 appears when ESM is activated while the motor data identification is still pending; the identification runs at the next switch-on command.
Codes next to this one
Source
Written from Siemens' own List Manuals and operating instructions; every number, designation and parameter on this page is checked against them before publication.
All SINAMICS codes: fault and alarm codes · the A07xxx group · SINAMICS manuals · Siemens manuals