STO hardware fault (_ecSTO_HARDWARE_FAULT)

What does 10034 mean?

This fault signals an internal hardware malfunction within the Safe Torque Off (STO) circuits, indicated by the assertion of one or both internal fault circuit outputs. This is a critical safety-related fault, occurring regardless of whether the drive is enabled or disabled, and means the STO function cannot be relied upon, risking uncontrolled torque.

Complete Troubleshooting Guide

1. 1

   Perform a power cycle of the drive to attempt a reset of the internal hardware.

2. 2

   If the error persists after power cycling, contact ABB technical support, as this indicates a persistent internal hardware failure in the STO circuits that may require drive replacement.

3. 3

   As a secondary check, still verify external STO input wiring and safety circuits, as external conditions might sometimes influence internal fault detection.