A31915 — Encoder 1: Configuration error

A31915 is raised when the drive detects that the configuration of encoder 1 is incorrect. The affected component is encoder 1 on the Sensor Module (Sensor Module Encoder 1). Depending on how the drive is configured, the same condition can also be output as a fault (F) or as a message without automatic reaction (N). Which configuration problem the drive has found is shown by the alarm value; the S120/S150 and G130/G150 manuals describe the message almost identically, with the S120/S150 manual additionally listing alarm values 2 and 3 for the cyclic DQ telegrams.

• The configuration set for encoder 1 is incorrect; the exact situation is given by the alarm value.
• Alarm value 1: encoder 1 was re-parameterized while a fault or alarm was present — the drive does not permit a re-parameterization between fault and alarm.
• Alarm value 2 (S120/S150): the cyclic DQ receive telegram is too long and is limited.
• Alarm value 3 (S120/S150): the cyclic DQ send telegram is too long and is limited.
• Alarm value 419: with the fine resolution (Gx_XIST2) configured, the encoder reports a maximum possible absolute position actual value (r0483) that can no longer be represented within 32 bits.

1. Read the alarm value in r2124 and interpret it as a decimal number; it tells you which of the configuration problems the drive has detected.
2. Alarm value 1: do not re-parameterize encoder 1 between fault and alarm — carry out the re-parameterization only when no fault or alarm is active.
3. Alarm values 2 or 3 (S120/S150): the manual gives no separate remedy; the cause text states that the overly long cyclic DQ receive or send telegram is limited by the drive.
4. Alarm value 419: reduce the fine resolution (p0419), or — if the complete multiturn range is not required — deactivate the monitoring (p0437.25).

• The message value is the alarm value; the manual instructs to read it in r2124 and interpret it as a decimal number.
• 1 — re-parameterization between fault/alarm is not permissible.
• 2 — the cyclic DQ receive telegram is too long and is limited (S120/S150).
• 3 — the cyclic DQ send telegram is too long and is limited (S120/S150).
• 419 — when the fine resolution Gx_XIST2 is configured, the encoder identifies a maximum possible absolute position actual value (r0483) that can no longer be represented within 32 bits.

• r2124 — alarm value: read here, interpreted as a decimal number, which configuration problem triggered A31915.
• p0419 — fine resolution of the absolute value Gx_XIST2 (in bits): for alarm value 419 the remedy is to reduce this resolution.
• p0437 — extended Sensor Module configuration: bit 25 (p0437.25) deactivates the monitoring of the fine resolution, used when the complete multiturn range is not required.
• r0483 — CO: encoder actual position value Gn_XIST2: with alarm value 419 this is the absolute position actual value whose maximum possible value no longer fits within 32 bits.

As an alarm, A31915 requires no acknowledgement and the drive takes no automatic action. If the drive outputs the same condition as a fault, the manual requires that it be acknowledged immediately.