F07970 — Drive: Automatic encoder adjustment incorrect

F07970 (Drive: Automatic encoder adjustment incorrect) is raised when the automatic encoder adjustment — the technique that determines the angular commutation offset — aborts because one of its internal checks has failed; the drive coasts down. The message value carries the fault value, which the drive stores in r0949 and which must be interpreted as a decimal number. The description for the S120 and S150 additionally contains fault value 24 for separately excited synchronous motors, while the G130/G150 description ends at fault value 17.

• The only cause the manuals give: an error occurred during the automatic encoder adjustment.
• What exactly failed is not listed separately — it is coded in the fault value (see the decoding below).
• On the S120 and S150, fault value 24 is reserved for separately excited synchronous motors and reports an excessive setpoint/actual value deviation of the excitation current: more than 50 % of the no-load excitation current during the excitation buildup phase, or more than 10 % at the end of the magnetizing phase.

1. Fault value 1 (current controller limited): check whether the motor is correctly connected, whether the motor data have been entered correctly, and replace the power unit involved.
2. Fault value 2 (motor shaft locked): open the motor holding brake (p1215 = 2) and bring the motor into a no-load condition.
3. Fault value 4 (encoder speed signal not plausible): check the speed actual value inversion (p0410.0), the motor connection, the encoder pulse number (p0408), the gearbox factors (p0432, p0433) and the motor pole pair number (p0314).
4. Fault value 5: deselect U/f (p1300) or deactivate encoder calibration (p1990).
5. Fault value 10: increase p0325, check whether the motor is correctly connected, replace the power unit involved.
6. Fault value 11: increase p0329, check whether the motor is correctly connected, replace the power unit involved.
7. Fault value 12: reduce p0325 and check whether the motor data have been entered correctly.
8. Fault value 13: reduce p0329 and check whether the motor data have been entered correctly.
9. Fault value 14: increase p0329.
10. Fault value 15: increase p0325.
11. Fault value 16: deactivate the technique (p1982).
12. Fault value 17: repeat the technique.
13. Fault value 24: check the excitation equipment; if there is no error, extend the runtime for the automatic encoder calibration via p1999 and repeat the technique.

• 1: Current controller limited.
• 2: Motor shaft locked.
• 4: Encoder speed signal not plausible.
• 5: Deselect U/f (p1300) or deactivate encoder calibration (p1990).
• 10: Stage 1 — the ratio between the measured current and zero current is too low.
• 11: Stage 2 — the ratio between the measured current and zero current is too low.
• 12: Stage 1 — the maximum current was exceeded.
• 13: Stage 2 — the maximum current was exceeded.
• 14: The current difference for determining the +d axis is too low.
• 15: The second harmonic is too low.
• 16: The drive converter is too small for the measuring technique.
• 17: Abort due to pulse inhibit.
• 24 (S120/S150 only, separately excited synchronous motors): a) after the monitoring time has expired, the setpoint/actual value deviation of the excitation current is more than 50 % of the no-load excitation current during the excitation buildup phase; b) at the end of the magnetizing phase, the deviation is more than 10 %.

• r0949 — the fault value of this message; read it as a decimal number to pick the right remedy.
• p0325 — motor pole position identification current, 1st phase: increase it for fault values 10 and 15, reduce it for value 12.
• p0329 — motor pole position identification current: increase it for fault values 11 and 14, reduce it for value 13.
• p0314 — for fault value 4, check whether the motor pole pair number entered here is correct.
• p0408 — rotary encoder pulse number: check it for fault value 4.
• p0410 — encoder inversion of the actual value: check bit 0 (p0410.0) for fault value 4.
• p0432, p0433 — gearbox factors for encoder revolutions and motor/load revolutions: check both for fault value 4.
• p1215 — motor holding brake configuration: p1215 = 2 opens the holding brake (fault value 2).
• p1300 — open-loop/closed-loop control operating mode: U/f must be deselected here (fault value 5).
• p1982 — PolID selection: deactivating the technique here is the remedy when the drive converter is too small (fault value 16).
• p1990 — encoder adjustment to determine the angular commutation offset: the calibration behind this fault; the remedy for value 5 is to deactivate it.
• p1999 — scaling for the angular commutation offset calibration/PolID: use it to extend the runtime of the automatic encoder calibration (fault value 24).

Acknowledge the fault immediately; the drive will not start again before this is done. Where the remedy ends with "Repeat technique" (fault values 17 and 24), restart the automatic encoder adjustment once the cause has been corrected. After fault value 16 the technique remains deactivated via p1982.