9455 is a clean and quiet protection switch for critical broadcast and satellite feeds. It switches cleanly between asynchronous sources which means it can be used live to air. The module has a full video frame synchronizer, rather than a line delay, ensuring perfect alignment of mis-timed and non-synchronous SDI sources. Clean and quiet switching between sources requires that they be synchronous and precisely timed to each other. It accomplishes this automatically, with integral frame synchronization of the inputs, allowing operation with both synchronous and asynchronous (wild) sources. This frame synchronization feature not only means that the output of the 9455 will always be stable and glitch-free, but it also means that in the event of a total loss of both inputs, consistently timed color black will still be output. These internal frame synchronizers can be genlocked to an external reference signal so that the output of the 9455 is synchronous to local sources. Alternately, in teleports, headends, and other multi-service facilities, where there is no logical common reference, the 9455 will internally generate an accurate reference.