F31138 — Encoder 1: Fault when determining the position (multiturn)

F31138 is raised when Encoder 1, a DRIVE-CLiQ encoder, reports a position determination fault: the multiturn part of the absolute position could not be determined. The S120/S150 manual titles the code Encoder 1: Fault when determining the position (multiturn), the G130/G150 manual Encoder 1: Internal error when determining multiturn information; both describe the same condition on the encoder.

• A position determination fault has occurred in the DRIVE-CLiQ encoder.
• The manual names no individual defect: which internal encoder condition triggered the fault is bit-coded in the fault value, together with the encoder version.

1. Read the fault value in r0949 and interpret it as a binary number: the upper byte (yy) identifies the encoder version, the set bits the detailed cause.
2. Match the set bits against the decoding in the fault value section for that version.
3. If the encoder version is not described in the manual, contact the encoder manufacturer for the bit coding.
4. If required, replace the DRIVE-CLiQ encoder.

The drive stores the cause as yyxxxxxx hex in r0949 (message value: fault cause, binary): yy is the encoder version, xxxxxx the bit coding of the fault cause. The bits that describe the multiturn condition itself:

• yy = 8 (0000 1000 bin): bit 17 — fault when determining the position (multiturn); the G130/G150 manual words this bit fault in the multiturn.
• yy = 11 (0000 1011 bin): bit 7 — rotation error counter (MT_ERR). This version is decoded in the S120/S150 manual only.
• yy = 14 (0000 1110 bin): bit 1 — position word 1 position determination error (multiturn); bit 17 — position word 2 position determination error (multiturn). This version is also decoded in the S120/S150 manual only.

The same fault value also carries bits for other encoder conditions — signal monitoring, LED monitoring, temperature, the safety status display (F1/F2), FPGA and power supply monitoring, and further position word errors; the manual decodes every bit. For an encoder version that is not described there, contact the encoder manufacturer.

• r0949 — fault value: read this code's cause here, interpreted binary, to identify the encoder version and the set cause bits before deciding whether the encoder must be replaced.

Acknowledgement is bound to pulse inhibit: the drive accepts the acknowledgement only while its output pulses are inhibited, so bring the drive into pulse inhibit, acknowledge the fault and only then restart. Because the fault points at the encoder, interpret the fault value first — if it flags the encoder itself, the remedy is to replace the DRIVE-CLiQ encoder.