LED Sending Card Explained How video data is sent from a source to an LED screen

An LED sending card is a key part of an LED screen control system. It takes video data from a source, such as a media player, computer or video processor, and sends that data to the LED display so the image can be shown correctly.

In simple terms, the LED sending card is the link between the content source and the LED screen. It prepares and transmits the signal to the screen’s receiving cards, which then distribute the image data across the LED modules.

What Is an LED Sending Card?

An LED sending card is an electronic control component used in LED display systems. Its role is to send video and control data from the input source to the LED screen.

The LED sending card does not usually display the image itself. Instead, it processes the incoming signal and sends the correct data to the receiving cards installed inside the LED screen cabinets.

This makes the LED sending card an essential part of the wider LED screen control system.

How an LED Sending Card Works

An LED sending card receives a video signal from a device such as:

A media player
A computer
A video scaling processor
A broadcast system
A control processor

The LED sending card converts that signal into data that the LED screen can understand. This data is then sent through network cables, fibre connections or other supported signal routes to the receiving cards in the screen.

The receiving cards then control the LED modules, telling each part of the display what brightness and colour to show.

Where the LED Sending Card Sits in an LED Screen System

A typical LED screen signal chain may look like this:

Content source
Video scaling processor or media player
LED sending card
LED receiving cards
LED modules

The LED sending card sits before the screen itself. It is part of the control and signal distribution stage, helping ensure the content reaches the correct parts of the display.

For a related explanation, see LED Receiving Card Explained.

LED Sending Card vs LED Receiving Card

LED sending cards and LED receiving cards work together, but they do different jobs.

An LED sending card sends the video data from the content source towards the LED screen.

An LED receiving card receives that data inside the LED screen and distributes it to the LED modules.

The LED sending card manages the outgoing signal. The LED receiving card manages the local display control within the screen.

Both are required for most professional LED display systems.

Why an LED Sending Card is Important

The LED sending card helps determine how reliably and accurately video data reaches the LED screen.

A correctly specified LED sending card supports:

Stable signal transmission
Correct screen resolution
Smooth content playback
Accurate image mapping
Reliable communication with receiving cards
Good compatibility with processors and control software

If the LED sending card is not suitable for the screen size, resolution or control system, the display may not show content correctly.

LED Sending Cards & Screen Resolution

LED screens are often built from multiple cabinets and modules. The final display size and pixel pitch determine the total pixel resolution of the screen.

The LED sending card must be capable of handling the amount of data required by that resolution.

For example, a small indoor LED display may need fewer sending card outputs than a large-format screen with a high pixel count. Larger or higher-resolution LED screens may need multiple sending cards or more advanced control hardware.

This is one reason why LED screen control systems are specified as part of the full display design.

LED Sending Cards & Video Processors

An LED sending card is often used alongside a video scaling processor.

The video processor prepares the content so it fits the LED screen correctly. It may adjust scaling, aspect ratio, input sources and image layout.

The LED sending card then sends the prepared signal to the LED screen control system.

For a more detailed explanation, see Video Scaling Processor Explained.

LED Sending Cards & Media Players

In some LED screen systems, a media player may work with the LED sending card to deliver scheduled or stored content.

The media player handles the content playback. The LED sending card handles the signal transmission to the LED display.

This setup is common in digital signage, retail displays, corporate screens and fixed LED installations where content needs to run reliably without constant manual control.

For more information, see Players Explained.

Common Applications for LED Sending Cards

LED sending cards are used in most professional LED screen systems, including:

Indoor LED video walls
Outdoor LED displays
Retail LED screens
Corporate reception displays
Broadcast and event screens
Digital signage networks
Large-format advertising screens

They are particularly important where image accuracy, stability and signal reliability matter.

Common Misunderstandings About LED Sending Cards

“An LED sending card is the same as a media player”
Not quite. A media player stores or plays content. An LED sending card sends the video data to the LED screen control system.

“The LED sending card controls every LED directly”
The LED sending card sends data to the screen, but the receiving cards inside the display usually control the LED modules directly.

“Any LED sending card will work with any LED screen”
Not always. LED sending cards must be compatible with the LED screen, receiving cards, resolution, processor and control software.