Blackmagic Design GPI and Tally Interface

Blackmagic Design GPI and Tally Interface

The Blackmagic Design GPI and Tally Interface is a compact network device that provides 8 contact closure inputs and 8 contact closure outputs for ATEM switchers and Videohub routers. It acts as a bridge between your digital switching environment and external hardware—such as tally lights, camera CCUs, or playback triggers—ensuring that everyone in the studio knows which source is "on-air."

Core Functionality

• Universal Tally Support: When connected to an ATEM switcher, the interface automatically triggers external tally lights to indicate Red (Program) and Green (Preview) status for specific cameras or sources.

• Input/Output Versatility: * 8 GPI Inputs: Can be used to trigger internal switcher actions (like a "Take" or a "Macro") from a physical foot pedal or external button.

  • 8 GPO (Tally) Outputs: Mechanical relays that close to ground to complete a circuit for external lights or to signal other equipment.

• Scalability: Since the device connects via Ethernet, you can add multiple interfaces to a single network. If you have a 40-input switcher, you can stack five units to provide 40 individual tally outputs.

Technical Features

• Opto-Isolated Inputs: The 8 inputs are optically isolated, protecting your expensive switcher from electrical spikes or ground loops occurring in external equipment.

• Ethernet Connectivity: Unlike legacy tally systems that require a direct serial connection, this unit connects to your network. This allows you to place the tally interface in a rack room or near the cameras while the switcher is in a different location.

• Standard 25-pin D-type Connector: All 16 signals (8 in / 8 out) are consolidated into a single industry-standard DB25 port, making it compatible with existing custom-soldered tally cables and patch bays.

Technical Specifications

Operational Insight (2026 Context)

In a 2026 production environment, this device remains the standard way to bridge "traditional" hardware with the ATEM ecosystem. While many modern cameras (like the Blackmagic Studio Camera line) receive tally signals over SDI or HDMI, the GPI and Tally Interface is essential if you are using:

1. Third-party cameras (Sony, Panasonic, JVC) that require a dry contact closure to trigger their built-in tally lights.

2. Custom tally boxes or large studio-floor tally displays.

3. Legacy Playback Decks that require a physical GPI trigger to start a clip synchronized with a switcher "Take."

Setup Tip: Because the device defaults to a specific IP range, it is best to connect it via USB to a computer first. Use the Blackmagic Videohub Setup or ATEM Setup utility to give it a static IP address that matches your production network before installing it in a permanent rack.