Two completely independent channels of detection monitor the two video inputs. Each channel has an indicator for the presence of sync, and an adjustable delay before sync loss notification occurs.

When a no sync condition still exists following the delay period, the no sync alarms are activated. The red no sync LED illuminates for the corresponding channel. An audible alarm (defeatable) is also activated. (The audible alarm may be permanently disabled if required.) The two form-C gold relay contacts for the channel are also switched, allowing external devices (such as the RI-2) to be controlled, or emergency backup audio to be routed.