Blackmagic ATEM Manual - Concept Music Art

21
Getting Started
GPI and Tally Interface
Sending Tally Signals via a GPI and Tally Interface
Your ATEM switcher can send tally signals to monitors and cameras to make it clear which source is on the
program output, i.e. which source is on air.
Tally is commonly used to light the red light on top of a camera or monitor so the talent knows they are on
air. Tally can also illuminate a border on a monitor such as a Blackmagic SmartView Duo or SmartView HD.
The border allows production staff to know which camera is on air.
The GPI and Tally Interface by Blackmagic Design, is an Ethernet device which provides eight mechanical
relay contact closures to ground that can be used for tally. Tally signals are sent from the Ethernet port of
your ATEM switcher to a GPI and Tally Interface on the same network as the switcher. By following the wiring
guide on the back of the GPI and Tally Interface, a breakout cable can be connected to video equipment
that supports contact closure tally signals, such as Blackmagic SmartView Duo and SmartView HD. Up to 8
tally receiving devices can be supported with the GPI and Tally Interface.
The GPI inputs are optical isolators which are triggered by connection to ground with a maximum of 5V
at 14mA.
The tally outputs are mechanical relay contact closures to ground with a maximum of 30V at 1A.
The following table illustrates which tally signal is fired when a switcher input is selected on the program
output.
Program Output
Tally signal
Switcher Input 1 Tally 1
Switcher Input 2 Tally 2
Switcher Input 3 Tally 3
Switcher Input 4 Tally 4
Switcher Input 5 Tally 5
Switcher Input 6 Tally 6
Switcher Input 7 Tally 7
Switcher Input 8 Tally 8