How would you know if the IFM is turned off?

• A. The IFM unit reports 'OFF' LED
• B. A warning beep sounds
• C. The IFM indicator shows no power
• D. No Power Status symbol (H,M,L) is displayed on FM1 line on EUFD

Answer: (D)

The key idea is how this system communicates power state. On the EUFD, the FM1 line shows a Power Status symbol—typically H, M, or L—to indicate the IFM’s power level when it’s powered. If the IFM is turned off, that Power Status symbol does not appear on the FM1 line. So, the lack of any Power Status symbol on FM1 is the clear, unambiguous signal that the IFM is not powered. Other indicators like a separate OFF LED or a warning beep can occur for various reasons or other conditions, but they don’t provide the definitive indication of the IFM’s power state like the missing symbol on the FM1 line does.