Issue
When manually binding the PowerFail system variable via a Numeric Input in the program header of a b3 controller, the value shown in the Binding Variables window may appear incorrectly (e.g., 1536 instead of a binary value like 1 or 0).
Product Line
EcoStruxure Building Operation
Environment
- b3 controllers
- Script Program Editor
Cause
The Script Program Editor for b3 controllers does not recognize PowerFail as a predefined system variable. As a result, it displays an unexpected integer value in the Binding Variables window.
Resolution
Despite the incorrect display (e.g., 1536), the PowerFail variable functions correctly when bound to a Numeric Input. During compilation and execution, the system properly interprets the value.
Best Practices for Scripting
- Treat
PowerFailas a binary input: use logic based onTrue/FalseorON/OFF. - Ignore the displayed integer value in the Binding Variables window.
- Be aware that
PowerFailis only active for one scan cycle immediately after power is restored following a loss.
Example Usage
Additional Notes
- This behavior is expected and does not impact the actual functionality of the
PowerFailvariable.
