Max Time Expired (Specific)

What does 0x40CB mean?

The 'MaxTimeExpired' flag within the FB Envelope function block is TRUE. This confirms that the maximum permissible time for the safety function output to be active has been reached, causing the output to switch off. This fault prioritizes safety by ensuring the output does not remain active beyond its design limit.

• Safety-relevant process condition (e.g., door open, E-Stop active) remaining in a hazardous state longer than the configured 'Max Time' (e.g., P5-01).
• Incorrect 'Max Time' parameter (e.g., P5-01) set too short for the required safe operating duration.
• Failure of a safety-rated actuator or interlocking device to achieve its safe state within the expected timeframe (e.g., safety door lock mechanism).
• External logic preventing the reset condition for the 'MaxTimeExpired' flag from being met (e.g., acknowledgement signal missing).

Click steps to track your progress.

1. 1

   1. Identify the specific safety function output that remained active and the condition that caused it.

2. 2

   2. Review the configured 'Max Time' parameter (e.g., P5-01) in the TwinSAFE logic for appropriateness against process requirements.

3. 3

   3. Verify the physical state and operation of all safety inputs (e.g., light curtain, safety switch at terminal S1-1) associated with the safety function.

4. 4

   4. Check all output conditions and interlocks that are designed to clear the safety function's active state.

5. 5

   5. Monitor the relevant process variables and safety inputs in real-time to observe the timing of events.