F32115 — Encoder 2: Amplitude error track A or B (A^2 + B^2)

F32115 monitors the two track signals of Encoder 2. The drive continually forms the combined amplitude of the pair — the square root of A^2 + B^2 — and compares it with the window the measuring system must hold: the nominal signal level of the encoder must lie between 375 mV and 600 mV (500 mV -25/+20 %). For Sensor Modules for resolvers (e.g. SMC10) the nominal signal level is 2900 mV (2.0 Vrms).

The two manuals draw the trip lines differently. On the S120/S150 the code is raised when the signal level falls below the permissible limit value: below 170 mV when the input frequency is at most 256 kHz, below 120 mV when it is above 256 kHz, and below 1070 mV with a resolver Sensor Module. On the G130/G150 the manuals describe the code as an amplitude error and also watch the upper side: the response thresholds are below 170 mV (observe the frequency response of the encoder) and above 750 mV, respectively below 1070 mV and above 3582 mV with a resolver Sensor Module.

Note: the analog values of the amplitude error are not measured at the same time with the hardware fault output by the Sensor Module. Depending on how the drive is configured, the same condition can also be signalled without a reaction (N) or as an alarm (A).

• The signal level that the drive computes across both tracks — the root from A^2 + B^2 — has left the permissible range around the nominal level.
• On the S120/S150 the drive writes the code when this level falls below the permissible limit value; on the G130/G150 the code is described as an amplitude that exceeds the permissible tolerance, so a level that is too high also trips it.

1. Check that the encoder cables and their 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, e.g. its contacts.
5. Measuring system without its own bearing system: adjust the scanning head and check the bearing system of the measuring wheel.
6. Measuring system with its own bearing system: make sure the encoder housing is not subjected to any axial force.

• The message value shows the two tracks as "A track: %1, B-track: %2".
• Fault value (r0949, interpret hexadecimal): yyyyxxxx hex.
• xxxx = signal level, track A (16 bits with sign).
• yyyy = signal level, track B (16 bits with sign).
• A signal level of 500 mV peak value corresponds to the numerical value 5333 hex = 21299 dec.
• A signal level of 2900 mV peak value corresponds to the numerical value 6666 hex = 26214 dec.

• r0949 — fault value of this code; read it in hexadecimal to obtain the measured signal levels of track A and track B at the moment of the fault.

The drive accepts the acknowledgement only when its power pulses are inhibited: bring the drive into a pulse-inhibited state (for example via OFF1, OFF2 or OFF3), acknowledge the fault and restart. When the same condition is signalled only as an alarm (A), the drive takes no reaction and there is nothing to acknowledge.