InValue Error (Specific)

What does 0x40CA mean?

The 'InValueError' flag within the FB Envelope function block is TRUE, indicating a specific issue with the input value. This signifies that the input signal is not valid or within the expected operational parameters, forcing the FB into a safe state. The fault provides the FB instance and the current InValue for diagnosis.

• Analog input signal is erratic or noisy, causing transient values outside the expected operating window (e.g., EMI from nearby VFD).
• Sensor provides an invalid or 'stuck' reading that falls outside the configured 'MinValid' and 'MaxValid' thresholds (e.g., P4-01, P4-02).
• Discrepancy detected between redundant analog inputs if configured, exceeding allowed deviation (e.g., P4-03 difference).
• Internal diagnostics of the analog safety input module (e.g., EL3102) detect an issue with the measurement path.

Click steps to track your progress.

1. 1

   1. Monitor the raw input signal (e.g., InValue) using a high-speed oscilloscope at the input terminals of the safety module (e.g., EL3xxx terminal X3).

2. 2

   2. Verify the sensor's output against a calibrated reference instrument.

3. 3

   3. Check the 'MinValid' (P4-01) and 'MaxValid' (P4-02) parameters in the FB Envelope configuration for correct range settings.

4. 4

   4. Ensure proper grounding and shielding of the analog input cable to minimize electrical noise.

5. 5

   5. Check for any internal diagnostic flags on the analog input safety module (e.g., EL3102) itself via TwinCAT System Manager.