A31999 — Encoder 1: Unknown alarm

A31999 tells the technician that the Sensor Module for encoder 1 has raised an alarm which the firmware in the Control Unit cannot interpret — the manuals call it an Unknown alarm. The manuals name the situation in which this happens: the firmware on the Sensor Module is more recent than the firmware on the Control Unit, so the Control Unit does not yet know this alarm. The number of the new alarm is output in the message value. Depending on how the drive is configured, the same condition can also be issued as a fault (F) or as a message with no automatic reaction (N).

• An alarm has occurred on the Sensor Module for encoder 1 that the Control Unit firmware cannot interpret.
• The firmware on the Sensor Module is more recent than the firmware on the Control Unit — the situation in which the manuals say this message can appear.

1. Read the alarm value in r2124 as a decimal number: it contains the number of the new alarm that the Sensor Module has issued.
2. If you need to know what this new alarm means, look it up in a more recent description of the Control Unit, as the note to this message recommends.
3. Compare the firmware versions: r0148 shows the Sensor Module firmware version, r0018 shows the Control Unit firmware version.
4. Apply one of the two remedies the manuals give: replace the firmware on the Sensor Module with an older firmware version, or upgrade the firmware on the Control Unit so that it can interpret the new alarm.

• The message value reads New message: %1 — the drive inserts the number of the new alarm raised on the Sensor Module for encoder 1.
• The alarm value is stored in r2124 and is to be interpreted as a decimal number; its content is the alarm number itself.

• r2124 (Alarm value) — holds the alarm value of this message; read it as a decimal number to obtain the number of the unknown Sensor Module alarm.
• r0148 (SM FW version) — shows the firmware version on the Sensor Module; the manual references it when an older Sensor Module firmware is to be loaded.
• r0018 (CU FW version) — shows the firmware version of the Control Unit; the manual references it when the Control Unit firmware is to be upgraded.
• p0491 (Motor encoder fault response ENCODER) — sets the drive's response to a motor encoder fault; the manual's note points to this parameter alongside this alarm.

As an alarm, A31999 requires no acknowledgment. If the drive configuration issues the same condition as a fault instead, it is acknowledged immediately with POWER ON. An acknowledgment alone does not resolve the firmware difference between Sensor Module and Control Unit — the manuals' remedies are the firmware measures described in the checks above.