Using Physical GPI to Select the Primary Input Source
How to use the rear panel GPI "Interface" connector to change the Primary Input Source.
Using external dry contact closures, you can use the rear panel "Interface" connector to change the Primary Input Source selection.
Here is the GPI "Interface" connector pinout.
This is a DB9-F connector on the rear panel for remote control input, using contact closures or other logic-level systems.
Pin 1: +5VDC Out
Pin 2: Input Common +
Pin 3: Trigger input #1
Pin 4: Trigger input #2
Pin 5: Trigger input #3
Pin 7,8,9: GND
For operation, a voltage must be applied to voltage input on pin 2. The +5V power output on Pin 1 may be used as the input voltage. If this is done, the trigger inputs may be tied to 5V or left floating for a "high" state, and tied to ground for a "low" state. In the below example Pins 1 & 2 are tied together.
Trigger Inputs 1 & 2 select the primary input source. The secondary source must be set manually.
Input #1 acts independently to select either the analog input on a falling edge (grounding Pin 3) or the AES input on the rising edge (un-grounding Pin 3):
Input #2 acts to select the LiveWire input on a falling edge (grounding Pin 4). On a rising edge (un-grounding Pin 4) the state of Input #1 is examined to select one of the other inputs: ("L" = grounded, "H" = un-grounded)
xLxx = LiveWire input
LHxx = Analog input
HHxx = AES input
If Inputs 1 and 2 have simultaneous transitions, Input 2 takes precedence. So LLxx and HLxx switch to LiveWire.
Input #3 is the manual failover trigger:
xxLx = trigger a manual failover. This will cause the secondary input to be selected and the failback logic to be activated.
xxHx = manually clear a failover. This will cause the primary input to be selected and normal failover logic to be activated.
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