A31920 — Encoder 1: Temperature sensor fault

A31920 reports that the evaluation of the temperature sensor connected to Encoder 1 has detected a fault: the measured sensor resistance lies outside the range that is plausible for the selected sensor type — either a wire breakage or a sensor that is not connected, or a resistance that is too low. The affected component is the Sensor Module Encoder 1; depending on the drive configuration, the same condition can also be issued as a fault or with no automatic reaction (N). The message value tells you which of the two causes the drive has detected and on which channel.

• While evaluating the temperature sensor, the drive detected a fault (component: Sensor Module Encoder 1).
• Fault cause 1 (01 hex): wire breakage or sensor not connected — the resistance is too high for the selected sensor type (KTY: R > 1630 Ohm, PT1000: R > 1720 Ohm).
• Fault cause 2 (02 hex): measured resistance too low (PTC: R < 20 Ohm, KTY: R < 50 Ohm, PT1000: R < 603 Ohm).

1. Check that the encoder cable is the correct type and is correctly connected.
2. Check the temperature sensor selection in p0600 to p0603 — the sensor type and signal source set there must match the sensor actually connected.
3. If the cause persists, replace the Sensor Module (hardware defect or incorrect calibration data).

• Message value: fault cause (%1) and channel number (%2).
• In r0949 (fault value) and r2124 (alarm value) the information is coded as 0000yyxx hex: yy = channel number, xx = error cause.
• xx = 01 hex: wire breakage or sensor not connected; xx = 02 hex: measured resistance too low.
• Additional values: only for internal Siemens troubleshooting.

• r0949 — fault value: read the coded cause of this message here (0000yyxx hex).
• r2124 — alarm value: contains the same coded information while the message is present as an alarm.
• p0491 — motor encoder fault response (ENCODER): the response parameter the manuals cross-reference for this message.
• p0600 — motor temperature sensor for monitoring: check here which temperature sensor is selected for the monitoring.
• p0603 — CI: motor temperature signal source: check the signal source from which the motor temperature is acquired.

No acknowledgment is required for this alarm, and the drive takes no automatic reaction on it. Your task is to eliminate the cause at the sensor — the encoder cable, the selection in p0600 to p0603, or the Sensor Module itself. If the drive is configured to output the same condition as a fault, the manuals specify immediate acknowledgment.