E-Stop Discrepancy Error - Input Group 2

What does FB ESTOP Bit 1 mean?

A discrepancy has been detected between the two channels of input group 2 for the FB ESTOP. This indicates that the redundant E-Stop input signals are not in agreement, suggesting a potential failure of one channel, a wiring issue, or an incorrect switching sequence. This will prevent the E-Stop function from operating safely and halt the machine.

• Mechanical failure or jamming of one of the redundant E-Stop button contacts for Input Group 2.
• Damaged insulation or a short circuit on one wire of the E-Stop input group (e.g., between signal and ground on channel X2.1).
• Safety controller input module fault on one channel of Input Group 2, misinterpreting the E-Stop signal.
• Excessive contact bounce from the E-Stop device, exceeding the configured discrepancy time (e.g., P_DISC_TIME_G2).
• Cross-talk or inductive coupling causing spurious signals on one E-Stop input channel.

Click steps to track your progress.

1. 1

   De-energize the safety circuit and verify the state of both redundant E-Stop input wires at the controller terminals (e.g., X2.1 and X2.2) using a multimeter.

2. 2

   Check the resistance of each individual E-Stop wire from the device to the safety controller input for Input Group 2 (e.g., from E-Stop switch terminal 3 to controller X2.1).

3. 3

   Replace the E-Stop button if visual inspection reveals significant wear, corrosion, or mechanical damage to its redundant contacts.

4. 4

   Review and adjust the discrepancy monitoring time parameter (e.g., P_ESTOP_DISCREPANCY_DELAY_G2) in the safety controller configuration.

5. 5

   Ensure proper cable shielding and grounding for the E-Stop circuit to mitigate potential EMI effects.