A31400 — Encoder 1: Alarm threshold zero mark distance error

Encoder 1 is monitored for its zero mark distance: the drive compares the distance between zero marks that it measures against the zero mark distance parameterized for the monitoring — p0425 for a rotary encoder, p0424 for a linear encoder. A31400 appears when the measured zero mark distance does not correspond to the parameterized one, i.e. the alarm threshold is exceeded. For distance-coded encoders the zero mark distance is formed from pairs of detected zero marks; depending on how the pairs are generated, a missing zero mark need not produce the message and then has no effect in the system. Depending on the drive configuration, the same condition can also be issued as a fault (F) or with no reaction (N).

• The zero mark distance measured by the drive does not correspond to the zero mark distance parameterized for the monitoring (p0425 for a rotary encoder, p0424 for a linear encoder).

1. Check that the encoder cables are routed in compliance with EMC.
2. Check the plug connections.
3. Check the encoder type — the monitoring expects an encoder with equidistant zero marks.
4. Adapt the parameter for the distance between zero marks (p0424, p0425).
5. Replace the encoder or the encoder cable.

• The alarm value is held in r2124 and is interpreted decimal: it contains the last measured zero mark distance in increments, where 4 increments correspond to 1 encoder pulse.
• The sign of the value designates the direction of motion when detecting the zero mark distance.

• p0424 — zero mark distance of a linear encoder; adapt this value when the measured distance of a linear encoder does not match the parameterization.
• p0425 — zero mark distance of a rotary encoder; adapt this value when the measured distance of a rotary encoder does not match the parameterization.
• r2124 — alarm value; read the last measured zero mark distance here, interpreted decimal (4 increments = 1 encoder pulse, the sign gives the direction of motion).

As an alarm, A31400 requires no acknowledgment and the drive does not change its state because of it. The same condition can also appear as a fault (F) or with no reaction (N): as a fault it is acknowledged IMMEDIATELY; with no reaction there is nothing to acknowledge.