Two-Hand Discrepancy Error - Between Pairs

What does FB TWOHAND Bit 2 mean?

A discrepancy has been detected between the actuation times of input pair 1 and input pair 2 for the FB TWOHAND. This means the operator is not actuating both hands simultaneously within the allowed time window, or there's an issue with the timing of the two-hand control device itself. This fault ensures true simultaneous actuation for safety and stops the machine.

• Operator actuation technique: one hand consistently actuates significantly before the other hand.
• Mechanical binding or slow response of one two-hand button assembly compared to the other.
• Excessive discrepancy time configured between input pairs (e.g., P_BetweenPairDiscTime) is too short for the application or operator.
• Voltage drop or intermittent connection affecting the response time of one entire input pair.
• Slight variation in switch bounce characteristics between the two separate input pair buttons.

Click steps to track your progress.

1. 1

   1. Observe the operator's hand placement and simultaneous actuation technique, providing retraining if necessary to ensure both buttons are pressed concurrently.

2. 2

   2. Measure the actuation and release times of each two-hand button assembly using a timing device or oscilloscope connected to the input terminals (e.g., X5.1 and X5.3).

3. 3

   3. Access the safety controller's programming interface and adjust the 'BetweenPairDiscTime' parameter (e.g., increase from 200ms to 350ms) to accommodate operator variance.

4. 4

   4. Verify the integrity of the 24VDC supply voltage to both two-hand button assemblies, checking for drops below 22VDC during actuation.

5. 5

   5. Check and clean the electrical contacts within both two-hand button assemblies for any foreign material that could impede consistent response.