F31116 — Encoder 1: Amplitude error monitoring track A + B

F31116 is raised by the amplitude/level monitoring of Encoder 1: the amplitude of the rectified encoder signals A and B is no longer inside the tolerance bandwidth. In the variant titled "Amplitude error monitoring track A + B", the monitored quantity also includes the amplitude from the root of A^2 + B^2, and both ends of the band are guarded — the measured level must stay above < 130 mV and below > 955 mV. In the variant titled "Signal level track A or B too low", the stated condition is the signal level of the rectified A and B signals falling below the permissible limit value, with the response threshold < 130 mV (observe the frequency response of the encoder).

Independently of the variant, the nominal level the encoder must deliver is fixed: The nominal signal level of the encoder must lie in the range 375 mV to 600 mV (500 mV -25/+20 %). Depending on the drive configuration, the same condition can also be output as an alarm or as a message without automatic reaction (A/N).

• The amplitude of the rectified encoder signals A and B — and, in the amplitude-error variant, the amplitude from the root of A^2 + B^2 — of Encoder 1 is not within the tolerance bandwidth.
• In the variant titled "Signal level track A or B too low", the signal level of the rectified A and B signals falls below the permissible limit value.
• Concretely, the measured level is below < 130 mV (observe the frequency response of the encoder) and, on the drives that also monitor the upper threshold, above > 955 mV.

1. Check that the encoder cables and the shielding are routed in compliance with EMC.
2. Check the plug connections.
3. Replace the encoder or the encoder cable.
4. Check the Sensor Module, for example its contacts.

• The fault value is stored in r0949 and is to be interpreted as hexadecimal yyyyxxxx hex.
• xxxx = signal level, track A (16 bits with sign).
• yyyy = signal level, track B (16 bits with sign).
• The message value is displayed as "A track: %1, B-track: %2", i.e. %1 is the track A level (xxxx) and %2 the track B level (yyyy).
• Reference point: a signal level of 500 mV peak value corresponds to the numerical value 5333 hex = 21299 dec.
• Note: the analog values of the amplitude error are not measured at the same time with the hardware fault output by the Sensor Module.

• r0949 — fault value: read it as hexadecimal yyyyxxxx to see the measured signal levels of track A (xxxx) and track B (yyyy), each 16 bits with sign.
• p0491 — Motor encoder fault response ENCODER: the manual cross-refers to this parameter for F31116; it defines the encoder-specific fault response that takes effect when this monitoring trips.

The fault is acknowledged immediately: once the cause has been rectified, the acknowledgment can be issued straight away and the drive restarted. In the alarm (A) and no-reaction (N) variants, the manual specifies no reaction and no acknowledgment.