Reset Error 2

What does C002 mean?

A static TRUE signal is detected at the Reset input of a safety function block (e.g., SF_EmergencyStop, SF_ESPE, SF_AOPD) while it is waiting for a primary safety input or during operation in a specific state (e.g., 8003). This condition prevents the safety function from resetting properly or clearing error states. Consequently, it keeps associated safety outputs in a safe (FALSE) state, inhibiting normal operation.

• Sustained electrical short circuit on the Reset input wiring (e.g., terminal X1.5) providing continuous 24VDC.
• The physical Reset push-button or associated relay contact is mechanically stuck in the closed position.
• Safety PLC logic (e.g., Beckhoff TwinCAT Safety) inadvertently maintaining the Reset input TRUE even during normal operation.
• Ground fault or insulation degradation in the Reset input wiring causing a spurious TRUE signal, particularly in harsh environments.
• Internal hardware fault within the safety input module causing the specific Reset input channel to register as continuously TRUE.

Click steps to track your progress.

1. 1

   Verify the voltage at the Reset input terminal (e.g., X1.5) with a calibrated multimeter to confirm if a persistent 24VDC signal is present.

2. 2

   Isolate the Reset input by disconnecting its physical wiring at the safety module and observe if the fault clears, indicating an external wiring or device issue.

3. 3

   Inspect the Reset push-button for mechanical binding or contamination; actuate it multiple times and verify its contact operation with an ohmmeter (continuity when pressed, open when released).

4. 4

   Review the safety PLC program logic (e.g., Siemens TIA Portal Safety, Rockwell Studio 5000) to ensure the Reset command is momentary and de-activates once the safety function is active.

5. 5

   Perform an insulation resistance test (Megger test) on the Reset input wiring if environmental factors (e.g., moisture, cutting fluids) are suspected.

6. 6

   If possible, swap the suspected input module with a known-good spare or re-route the input to an unused channel to diagnose module failure.