PI Feedback Loss

What does FBL mean?

This fault occurs when PI Feedback Loss Detection is programmed to fault (b5-12 = 2) and the PI Feedback is below the PI Feedback Loss Detection Level (b5-13) for the PI Feedback Loss Detection Time (b5-14). The PI Feedback source (e.g., transducer, sensor, building automation signal) is not installed correctly or is not working, risking unstable control.