Resolving issues regarding Axia GPIO for on-air lights is a topic that comes up on a regular basis, and this month's Tech Tip question was a good reminder that we need to cover it again!
Derrick Ginter of KTXT-FM at Texas Tech writes: "I am curious about the pinouts for GPIO on the Axia PowerStation, as I'm trying to wire up an on-air lamp. Right now, the control room monitor is assigned to GPIO channel 1. Is there something needed as a go-between from the 15-pin port to a relay? I'm not getting any continuity from pin 1 and while the solution may be simple- it's eluding me! I have a 12-volt power supply that I'd like to use to energize a relay that will itself, connect power to a 120v on-air lamp. My question is, how do I route the 12v power circuit through the GPIO pins to energize the relay?"
Matt Rockwell of Telos Tech Support replies: "The GPIO interface is the same for all Axia devices, and is documented in the manuals for each device that uses GPIO. The best documentation on using GPIO is actually in the xNode manual.
"Starting on page 31, the xNode manual has excellent documentation on pin configurations along with simple schematics on how to wire exactly what you are trying to do. Note that since this is all solid state and not physical relays on the device side, polarity will be very important. Figure 8-5 is what you are trying to do:
"As long as you have some GPIO channel number set in the show configuration for the CR Monitor channel (arbitrary and not the same as any existing Livewire channel) and the same channel number is assigned to the physical GPIO port, then Pin 1 will go low (closure) every time the Control Room monitors mute."