The 7465 Sync Changeover Switch module can be used with Avenue’s 7400 SPG module, or with third party sync pulse generators. In the event of a failure of the primary sync source, the 7465 changes to the secondary source. There are three poles or sections on the 7465. One pole tests for HD SDI and SD SDI signals. The other two poles test for AES audio, Composite video, Bi-Level Sync and Tri-Level Sync. A drop in signal amplitude below a predetermined auto threshold will trigger the switch.