Re: Blackmagic Tally and GPI for ATEM

there is not much too it. There is no documentation from Blackmagic - it's all silk screened on the Blackmagic Tally and GPI box. You use a 25 pin male connector for your hookup. You need to be able to use a soldering iron.

I hooked up a cheapo 12VDC power supply to some LED modules we found in a surplus store - the resistor for the LED was already in the module. the LED module just had red and black wires coming out of it. We plugged in the 12VDC power supply to make sure the lights lit up. (LED's are +5VDC, so this module was configured to accept a 12V DC signal.). We extended the cables from the LED module that lived on each camera with a cable, back to the switcher electronics lived in the control room - this is also where the Blackmagic Tally box lives (it hooks up to an ethernet port - we have a cheap switch in the control room for the Blackmagic switcher, the tally box, and the computers running the ATEM).

I soldered all the black wires (ground) of the LED modules to the tally points on the 25 pin connector (as shown on the silk screen of the Tally and GPI box). I tied all the red wires together, and connected this to the + of the 12VDC power supply. I connected the - of the power supply to the GND of the 25 pin connector (as shown by the silk screen). That's it. Plug in the power supply, and switch away - and the lights light up on the camera.

Had I spend more time, I would have used a larger box with a barrier strip with screw terminals to make everything neater - but I was in a rush, and threw this together, and it worked wonderfully.

Bob Zelin