Two-Hand Discrepancy Error - Input Pair 1

What does FB TWOHAND Bit 0 mean?

A discrepancy has been detected within the two channels of input pair 1 for the FB TWOHAND. This means the redundant hand actuation signals are not synchronizing correctly, indicating a potential issue with the two-hand device, its wiring, or incorrect timing. This will prevent safe two-hand operation and put the machine into a safe state.

• One two-hand control button (e.g., H1 or H2) is stuck in the actuated position or has a faulty internal contact.
• Operator is not actuating both two-hand buttons (e.g., S3 and S4) simultaneously within the allowed discrepancy time (e.g., P_TWOHAND_WINDOW).
• Damaged cable or loose connection to one of the two-hand control buttons (e.g., terminal X14.1 or X14.2).
• Electrical noise or transient signals on one of the two-hand input channels, causing a false actuation signal.
• Discrepancy time parameter (e.g., P_TWOHAND_SYNCH_DELAY) is set too short for operator reaction time or button switch characteristics.

Click steps to track your progress.

1. 1

   Observe the input status LEDs (e.g., H1_IN, H2_IN) on the safety controller while an operator actuates both two-hand buttons simultaneously.

2. 2

   Measure continuity across the output contacts of each two-hand button (e.g., H1: 13/14, H2: 23/24) when pressed and released.

3. 3

   Verify the wiring resistance from each two-hand button's output contacts to the corresponding safety controller input terminals (e.g., from H1 14 to FB_TWOHAND_IN1).

4. 4

   Adjust the two-hand discrepancy time parameter (e.g., P_TWOHAND_MAX_DELAY) in the safety controller configuration to allow for operator actuation variation.

5. 5

   Confirm the two-hand control device itself is mechanically sound and not obstructed, preventing full and simultaneous actuation of both buttons.