InValue Expired (Negative)

What does 0x40C8 mean?

The input value (InValue) has expired, and its current state is below zero. This suggests that the input signal has either become invalid or has dropped below its expected range, leading to a safety state. The fault provides the FB instance, the current InValue, and the MinAllowedValue for detailed diagnosis.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Review the configured minimum allowed value ('MinAllowedValue') in the FB Envelope parameters; ensure it is appropriate for the application.

2. 4

   Use TwinCAT diagnostics to observe the 'InValue' in real-time and correlate it with the 'MinAllowedValue'.