N32415 — Encoder 2: Amplitude alarm track A or B (A^2 + B^2)

N32415 reports that the signal level of Encoder 2 is outside the permissible tolerance. The signal level is the root of A^2 + B^2 — the combined amplitude of tracks A and B. The manuals print the code as Amplitude alarm track A or B (A^2 + B^2) and as Signal level track A or B outside tolerance (alarm); the G130, G150, S120 and S150 manuals describe the same condition.

The nominal signal level of the encoder must lie in the range 375 mV to 600 mV (500 mV -25/+20 %). The response threshold is below 230 mV (observe the frequency response of the encoder). A signal level of 500 mV peak value corresponds to the numerical value 10650. For Sensor Modules for resolvers (e.g. SMC10), the nominal signal level is 2900 mV (2.0 Vrms) and the response threshold is below 1414 mV (1.0 Vrms); a signal level of 2900 mV peak value corresponds to 3333 hex = 13107.

Depending on how the drive is configured, the same condition can also be issued as a fault (F) or an alarm (A) instead of the reaction-free message. A neighbouring signal for the same encoder input, N32800 (Encoder 2: Group signal), is described on its own page.

• The signal level of encoder 2 — the root of A^2 + B^2, i.e. the combined amplitude of tracks A and B — lies outside the permissible tolerance.

1. Check the speed range: the frequency characteristic (amplitude characteristic) of the measuring equipment may not be sufficient for the speed range being used.
2. Check that the encoder cables and shielding are routed in compliance with EMC.
3. Check the plug connections.
4. Replace the encoder or the encoder cable.
5. Check the Sensor Module (e.g. its contacts).
6. If the coding disk is soiled or the lighting has aged, replace the encoder.

• The message value reads Amplitude: %1, Angle: %2.
• The alarm value is stored in r2124, to be interpreted in hexadecimal as yyyyxxxx hex: yyyy is the angle, xxxx is the amplitude, i.e. the root of A^2 + B^2 (16 bits without sign).
• The angle 0 ... FFFF hex corresponds to 0 ... 360 degrees of the fine position. Zero degrees is present at the negative zero crossover of track B.
• Note: the Sensor Module does not measure the analog values of the amplitude error at the same time as its hardware fault output.

• r2124 (alarm value): holds the value of this message — read it in hexadecimal as yyyyxxxx, where the upper half yyyy is the angle and the lower half xxxx the amplitude (root of A^2 + B^2, 16 bits without sign).

No operator acknowledgement is needed for this code. In its basic form it is a message without a reaction, so the drive does not change its operating state. When the drive's configuration raises the same condition as a fault, it is acknowledged immediately; as an alarm it likewise requires no acknowledgement. The indication only stops once the signal level is back inside the tolerance, so work through the checks above.