If the only operative ED is displaying a status or synoptic page and a DCU warning occurs, what should happen?

• A. Operable ED powers down.
• B. The operable ED will revert to the primary page and the warning message will be displayed.
• C. All pages are held and no warning is shown.
• D. System switches to ED3.

Answer: (B)

When a DCU warning occurs, the system prioritizes making the warning visible to the operator. If the only operative display is showing a status or synoptic page, it should switch back to the primary operational page so the warning message is displayed where the operator expects to see important alerts. This ensures the warning isn’t hidden on a diagnostic view and that the operator can promptly respond, without powering down or holding all pages, and without unnecessarily switching to a different ED.