The SDI Presence Detector with GPI from Link Electronics monitors two serial component digital signals and automatically switches to a backup auxiliary source in the event of a signal failure. This module also features "audio follow video" functionality, which is switched internally with a captive-screw terminal sub-module. This unit supports both Composite and Component video signals.
This unit's input receiver device monitors the incoming signal level and produces a DC voltage proportional to the amount of gain and equalization necessary to recover and reshape the signal. If automatic gain/EQ voltage exceeds the threshold voltage, this device will switch to auxiliary input.
Adjustment features give this unit the ability to select auxiliary input before data errors are visible in the primary input. Front panel switches allow you to override the automatic changeover functions and choose either video source. Dual front-panel LEDs indicate the presence or absence of video input signals. Switching is accomplished with an active 2:1 multiplexer and a 75Ω matched-impedance relay allows the input signal to pass through even if power is lost.