Muting EDM Monitoring Error - EDM2

What does FB MUTING Bit 5 mean?

An External Device Monitoring (EDM) error has been detected for the EDM2 feedback loop of the FB MUTING. This indicates a fault in the external safety output circuit (e.g., safety contactors) or its feedback path, which should confirm that the outputs have switched correctly in response to a muting event. This prevents unsafe operation if the outputs fail to respond, leading to a safety stop.

• Faulty auxiliary contact on the external safety contactor (e.g., K2) in the EDM2 feedback circuit.
• Open circuit or high resistance in the wiring of the EDM2 feedback loop (e.g., auxiliary contact 'NC' wire from K2 to safety input Y2.1).
• Mechanical binding or failure of the safety contactor K2 preventing proper switching and feedback.
• Incorrect wiring of the EDM2 feedback, such as using a normally open (NO) contact where a normally closed (NC) is expected.
• Excessive contact wear on the auxiliary contacts of K2, leading to intermittent feedback signal.

Click steps to track your progress.

1. 1

   1. Power down the system, then inspect and test the auxiliary contacts of the safety contactor K2 using a continuity tester to confirm proper NO/NC switching.

2. 2

   2. Measure the total resistance of the EDM2 feedback loop (e.g., from safety output Y2.0 to safety input Y2.1) to identify any breaks or high resistance connections.

3. 3

   3. Verify the mechanical operation of safety contactor K2, ensuring its armature moves freely and fully when energized and de-energized.

4. 4

   4. Confirm the wiring diagram matches the physical wiring of the EDM2 feedback loop, especially the type of auxiliary contact used on K2.

5. 5

   5. Observe the diagnostic status of EDM2 in the safety controller's software interface while attempting to reset the fault.