F32131 — Encoder 2: Deviation position incremental/absolute too large

F32131 reports that encoder 2 has failed a position plausibility check. With an absolute encoder the drive reads the absolute position cyclically and compares it with the incremental position; if the difference is excessively high, the message is issued and the absolute position that was just read is rejected. With an incremental encoder the check takes place when the zero pulse is passed. The manuals for the G130, G150, S120 and S150 describe the fault identically. Depending on the drive configuration, the same condition can also be issued as an alarm (A) or without any reaction (N).

• Absolute encoder: when the absolute position is read cyclically, an excessively high difference to the incremental position was detected, and the absolute position that was read is rejected.
• Limit for this deviation: for an EnDat encoder the limit is supplied from the encoder itself and is a minimum of 2 quadrants (e.g. EQI 1325 > 2 quadrants, EQN 1325 > 50 quadrants); for other encoders it is 15 pulses = 60 quadrants.
• Incremental encoder: when the zero pulse is passed, a deviation in the incremental position was detected.
• With equidistant zero marks, the first zero mark passed supplies the reference point for all subsequent checks; the other zero marks must lie at n times the distance referred to the first zero mark.
• With distance-coded zero marks, the first zero mark pair supplies the reference point for all subsequent checks, and the other zero mark pairs must have the expected distance to the first zero mark pair.

1. Check that the encoder cables are routed in compliance with EMC.
2. Check the plug connections.
3. Replace the encoder or the encoder cable.
4. Check whether the coding disk is dirty or whether strong ambient magnetic fields are present.
5. Adapt the parameter for the clearance between the zero marks (p0425).
6. If the message is output above the speed threshold, reduce the filter time if necessary (p0438).

• The drive enters the measured deviation into r0949; interpret this value as a decimal number.
• The value is the deviation in quadrants, where 1 pulse corresponds to 4 quadrants.

• p0425 (encoder rotary zero mark distance): the clearance between the zero marks — the parameter to adapt when the zero mark check on the incremental encoder trips.
• p0438 (square-wave encoder filter time): if the message is output above the speed threshold, reduce this filter time if necessary.
• r0949 (fault value): shows the deviation for this fault, in quadrants with decimal interpretation (1 pulse = 4 quadrants).

The fault must be acknowledged before the drive can be started again, and the acknowledgement is only accepted while the pulse inhibit is active. When the drive is configured to issue this condition as an alarm (A) or with no reaction (N), the manual specifies neither a reaction nor an acknowledgement — there is then nothing to reset.