Glossary A–ZLetter S
Sending card (LED controller)
A sending card is the control unit of an LED wall that accepts the video signal from a player or computer and converts it into data packets for the receiving cards in the wall's cabinets.
It usually sits in a separate device, the LED controller. This is the bridge between ordinary video equipment and the wall.
The controller accepts signals via HDMI, DisplayPort or similar connections and sends the data over network cables or optical fibre to the cabinets. During setup, it is defined which cabinet shows which section of the picture. There are two modes of operation: synchronous controllers show live what the connected source delivers; asynchronous controllers have their own storage and play content independently, even without a connected computer.
Each output of a controller can only supply a limited number of pixels; large walls therefore need several outputs or devices. Sending and receiving cards must belong to the same system. Operators should back up the configuration, ensure a spare controller or at least access to the setup software, and clarify whether the controller can be monitored remotely.