F33123 — Encoder 3: Signal level A/B outside tolerance

F33123 reports that the unipolar signal level of the A/B tracks of Encoder 3 has left the permissible window. The nominal unipolar level of the encoder must lie at 2500 mV +/- 500 mV; the drive responds when a level falls below 1700 mV or rises above 3300 mV. The level is only evaluated when the Sensor Module properties are available (r0459) and monitoring is active (p0437); outside these conditions the drive does not monitor the signal level at all. Depending on the drive configuration, the same condition can also be issued as an alarm (A) or with no reaction (N) instead of this fault.

• The unipolar level of one of the two signal pairs of Encoder 3 — AP/AN or BP/BN — is outside the permissible tolerance around the nominal signal level.

1. Make sure that the encoder cables and the shielding are installed in an EMC-compliant manner.
2. Check the plug connections and the contacts of the encoder cable.
3. Check for a short-circuit of a signal cable with mass or with the operating voltage.
4. Replace the encoder cable.

The drive enters the fault cause into r0949 as a binary value ("Fault cause: %1 bin"). Interpret the value bit by bit:

• Bit 0 = 1: either AP or AN is outside the tolerance.
• Bit 16 = 1: either BP or BN is outside the tolerance.

• r0949 — read the fault value here and interpret it in binary; bit 0 points to the AP/AN pair, bit 16 to the BP/BN pair.
• r0459 — check here that the Sensor Module properties are available; only then does the drive evaluate the signal level of Encoder 3.
• p0437 — check here that monitoring is active; without it the signal level of Encoder 3 is not evaluated.

The fault must be acknowledged immediately. Once the signal level is back inside the permissible range and the fault has been acknowledged, the drive can be started again.