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ABB Error 71391 — System signal configuration fault

Error

ABB 71391 (“System signal configuration fault”): System signal configuration: "An error occurred while configuring system I/O signal <name>." Recorded on the MotorOff and AutoOn system signals. Likely part: Configuration de signal système (Configuration de signal système).

Updated 2026-10-22 · LogrobotLM reference

What it means

System signal configuration: "An error occurred while configuring system I/O signal <name>." Recorded on the MotorOff and AutoOn system signals.

What to check

  • A system signal that cannot be configured at start-up means that the cabinet will be able neither to switch off the motors nor to switch to automatic via this path.
  • Check that the unit carrying the signal is present and powered — the error typically appears when the bus is absent at start-up.
  • Then check the signal declaration in the I/O configuration.
  • Note: In the field log, both occurrences (MotorOff, AutoOn) occur 31 seconds after a bus off (71301): the configuration was run while the bus was still absent. Restarting once the bus is stable is then sufficient — this is not a configuration error.

Part to check / replace

ABB 71391 points to the hardware below — start here before ordering.

Tap a part for every code that points to it — and verify the exact variant for your controller before ordering.

Related codes

41555I/O unit / Bus cable / Process equipment fault71058I/O unit communication lost7129924 V DeviceNet power supply fault

Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →