USM Ultimate Sports Manager
Download nowSign up

LED perimeter board glossary The words around the wall.

The terms that come up when a club buys, installs or runs LED perimeter boards, from the cabinet to the sponsor minutes. Each one is defined plainly first, and then, where it helps, placed on a real stadium rig.

Written by Thibaut Bollen, Maxamaze. .

All the LED guidesTalk to us

The hardware.

What a wall is made of, from the diode to the box that feeds it.

Cabinet
A cabinet is the self-contained unit an LED wall is built from: a frame holding LED modules, a receiving card and a power supply. A perimeter board is a line of cabinets bolted end to end. The USM interface calls each one a panel.How a perimeter board works
Module
A module is the smallest replaceable LED board inside a cabinet, a circuit board carrying the LEDs and the chips that drive them. A cabinet holds several modules side by side, and a technician can change a failed one without taking the whole cabinet out of the line.
Pixel pitch
Pixel pitch is the distance from the centre of one pixel to the centre of the next, in millimetres, written as P and a number: P10 means 10 mm. A smaller pitch puts more pixels into the same board. UEFA asks for 12.5 mm or less in the Champions League, and Lotto Park’s perimeter and mid-tier ribbon run at P6 and P12.What UEFA asks for
Real and virtual pitch
Real pitch is the physical spacing of the LEDs. Virtual pitch is a finer figure a panel claims by sharing diodes between neighbouring pixels, on panels whose red, green and blue diodes are mounted separately. It can look sharper on still images and add artefacts on moving content, so compare panels on real pitch. The Bundesliga accepts either, and calls the shared layout Pixel Share Mode.
SMD
SMD (surface-mounted device) describes an LED package that holds the red, green and blue diodes in one small component soldered onto the module, usually called 3-in-1 SMD. It gives a wider viewing angle and more even colour than the older DIP design with separate diodes, and UEFA’s club competition specification names 3-in-1 SMD for perimeter boards.What UEFA asks for
Receiving card
A receiving card is the control board inside each cabinet that takes pixel data from the Ethernet cable, keeps its own cabinet’s part of the picture and drives the modules. Receiving cards also report back: on NovaStar systems USM reads each card’s temperature, humidity and voltage about every 10 seconds and warns at 60 °C.LED monitoring
Sending card
A sending card converts the video signal from a computer into the Ethernet data that receiving cards read, and splits the picture across its output ports. It can sit in a PC, but on a stadium rig it is usually built into the LED processor, where it also stores the cabinet map and the main and backup port settings.
LED processor
An LED processor, or controller, is the box between the playout PC and the wall: it takes a DVI, HDMI or DisplayPort signal and sends each cabinet its pixels over Ethernet. On a perimeter it maps pixels one to one and does no scaling, so the software has to deliver exact geometry.What LED boarding software does
NovaLCT
NovaLCT is NovaStar’s Windows configuration software for its LED processors, sending cards and receiving cards. Installers use it to set up the cabinet map, brightness, colour settings and main and backup data ports. It is mostly used at installation and when a cabinet is replaced; during a match the processor runs on the settings NovaLCT saved into it.LED monitoring
EtherCON
EtherCON is Neutrik’s ruggedised RJ45 connector: a standard Ethernet plug in a locking metal shell built for touring and outdoor use. On LED processors such as the NovaStar MCTRL4K, the EtherCON sockets are the data outputs to the receiving cards, one cable per chain of cabinets. The MCTRL4K has 16 of them.
Backup data line
A backup data line is a second Ethernet cable that reaches a chain of cabinets from the far end, so that a cut cable or a failed cabinet leaves the rest of the chain fed from the other side. UEFA’s specification calls this a data ring loop. USM’s monitoring reports when part of a wall is running on its backup line.LED monitoring
Hot-swap
Hot-swap means replacing a module, cabinet or power supply while the rest of the wall stays powered and running. Perimeter boards are built for it because a match does not stop for repairs. UEFA’s specification asks for modules that can be swapped in under a minute and at least two spare cabinets on site.What UEFA asks for

The picture.

The words for how the picture looks, on the wall and on camera.

Nit
A nit is the unit of luminance, one candela per square metre (cd/m²), and the usual way to state how bright an LED board can get. Outdoor stadium boards need a high figure to stay readable in daylight. Indoor screens typically run far lower.What UEFA asks for
Gamma
Gamma is the curve that maps input values to light output, set so that the steps from dark to light look even to the eye and to a camera. The LED processor applies it to the whole wall.
Colour temperature
Colour temperature describes the tint of white on a display, in kelvin: lower values look warmer and more yellow, higher values cooler and bluer. LED walls are calibrated to one white point, typically around 6,500 K for video, so that cabinets from different production batches show the same white side by side.
Refresh rate
Refresh rate is how many times per second the driver chips redraw the picture on the LEDs, in hertz, and it decides whether a board flickers or shows dark bands on camera. It is a property of the panel and has nothing to do with the video’s frame rate. UEFA asks for at least 2,800 Hz in the Champions League and 1,800 Hz in the other club competitions.What UEFA asks for
Scan rate
Scan rate describes how many rows of LEDs one driver output lights in turn, written as a fraction such as 1/8 or 1/16 scan. A 1/16 scan module lights one row in sixteen at any instant and cycles through them fast enough to look continuous. Lower ratios give each LED more time lit and so more brightness, which is why outdoor boards favour them.
Grayscale bit depth
Grayscale bit depth is the number of brightness steps each colour of an LED can show, expressed in bits. More bits give smoother gradients and cleaner dark tones. It matters most when a board is dimmed for an evening match, because a panel with a low bit depth loses its darkest shades first.
Moiré
Moiré is the pattern of wavy lines or colour bands that appears when a camera sensor’s pixel grid interferes with the pixel grid of an LED board. It depends on pixel pitch, lens, distance and focus. Camera crews reduce it by changing position, zoom or focus, and board makers by using a finer pitch or a diffusing surface.
Genlock
Genlock locks the timing of a video device to an external reference signal, so that every device in a chain starts each frame at the same instant. On an LED wall it keeps the processor’s output in step with broadcast cameras or with other walls. It is set up on the processor and the broadcast equipment, and matters most in studios and large television productions.
EDID
EDID (Extended Display Identification Data) is the block of data a display sends to a computer to say which resolutions and refresh rates it accepts. An LED processor presents its own EDID to the playout PC. Some processor EDIDs describe 50 Hz as 49.9 Hz, which Windows reports as 49, and USM treats that as 50 when matching frame rates.
Frame rate
Frame rate is the number of new pictures the playout sends per second, written as fps or with p for progressive, as in 50p. Stadiums in Europe usually run at 25 or 50, matching local television. USM offers 25, 30, 50 and 60 and reads the display’s refresh rate to pick a matching mode, because a mismatch plays video at the wrong speed.
Judder
Judder is uneven motion that appears when frames stay on screen for unequal lengths of time, usually because some are repeated or dropped between a source and a display running at different rates. On a perimeter it shows most on scrolling text.

The boards.

The kinds of LED board a stadium has, and where each one stands.

Perimeter board
A perimeter board is a line of LED cabinets standing around the edge of a pitch, facing the main cameras, that shows sponsor advertising during a match. In football it runs along the touchlines and behind the goals, and UEFA asks for at least 90 cm of display height in the Champions League.How a perimeter board works
Fascia
A fascia board is an LED strip mounted along the front edge of a stand, typically between the lower and upper tiers. It sits further from the pitch than the perimeter and is seen by the crowd and the wide cameras. At Lotto Park the mid-tier ribbon and the perimeter change on the same frame.How a perimeter board works
Ribbon board
A ribbon board is a long, narrow LED display, many times wider than it is tall, run along a stand or around an arena bowl. The term comes from North American venues and is often used for fascia boards. For playout it presents the same problem as a perimeter: a very wide strip that has to be folded into a standard video signal.What LED boarding software does
360° ribbon
A 360° ribbon is a ribbon board that runs all the way round a stadium or arena bowl without a break. Content can run as one picture round the full circle or be split into sections. Because the strip closes on itself, its first and last pixels meet, and a scrolling message has to cross that join without a jump.
Mini-board
A mini-board is a small, low LED board placed behind the goal nets, below the line of the main perimeter. In German it is a Minibande. The Bundesliga limits them to 30 cm high and 8 m wide, and allows only still images on them: at most two adverts a match, each at least five minutes long.The league rules
Camcarpet
A camcarpet is an advertising surface laid flat on the ground beside the goal, drawn in perspective so that it appears to stand upright in the main camera’s picture. Most are printed and carry one sponsor for the whole match. LED camcarpets exist too; in the Bundesliga they need the league’s approval and show still images of at least 45 minutes.The league rules

The content.

How artwork is laid onto a wall and put in order.

Canvas
A canvas is the full picture the playout software renders for one output, of which the wall’s pixels may be only a part. On a folded perimeter the canvas is a standard video mode large enough to hold every row: a 3840 x 1296 wall can run on a 3840 x 2160 channel, with the wall’s pixels rendered 1:1 at a known position.Artwork sizes and the fold
Fold
Folding is how a perimeter far wider than any video signal fits into one: the strip is cut into rows at the output width and the rows are stacked, and the LED processor maps each row back into its place on the ground. For example, 84 cabinets of 192 x 144 on a 3840-pixel output give 20 per row, four full rows and four cabinets on a fifth.Artwork sizes and the fold
Row
A row is one horizontal band of a folded canvas, carrying one stretch of the physical board. Rows are usually as wide as the output, but a wall built from mixed cabinet sections can have rows of different widths, such as 3840, 3200, 3840 and 3200 pixels. The software then has to fold the strip at each row’s own width.Artwork sizes and the fold
Offset
An offset moves content a set number of pixels from where the grid would put it. An x offset shifts a banner sideways along the strip. A row offset leaves a black band at the top or bottom of every row, so that a 128-pixel row with a 32-pixel offset carries 96 pixels of content, which USM sets per screen when the screen is created.Artwork sizes and the fold
Span
Span is how many cabinets a piece of artwork covers along the board. A banner can span several cabinets as one continuous picture, crossing the join between folded rows. A span can be fractional: 4.25 cabinets of 192 pixels is a banner 816 pixels wide.Artwork sizes and the fold
Spot
A spot is one paid appearance of a sponsor in a rotation, lasting a set number of seconds. Spot length is agreed in the contract and is usually the same for every sponsor on a board. USM’s builder for synchronised playlists across two screens requires one spot length, so that both screens change at the same moment.
Sequence
In playout software, a sequence is a saved arrangement of artwork on a wall: which media sits on which cabinets, and how it is scaled, cropped and spanned. It is prepared before the match and reused. In USM Boarding a sequence is one finished banner layout for one screen, and playlists are built from sequences.What LED boarding software does
Playlist
A playlist is an ordered list of items, each with a duration, that a playout system plays on one screen, moving to the next item on its own when each one ends. It is the running order the operator watches during a match. In USM Boarding each playlist belongs to one screen and is a list of sequences.What LED boarding software does
Cue
A cue is a prepared instruction the operator fires at a known moment, usually with one key, to change what plays. In USM Boarding a cue says which playlist runs on which screen, so one key press can switch several walls on the same frame. Cues sit on the function keys.What LED boarding software does

Selling the airtime.

How the time on the boards is sold and shown to have run.

Rotation
A rotation is the repeating cycle of sponsor spots on a board during a match, each sponsor holding the wall for its contracted seconds before the next takes over. It runs through each half and is interrupted for goals and other moments. USM then resumes the rotation where it stopped, and the interrupted sponsor is still owed its time.What LED boarding software does
Proof of play
Proof of play is the record of what appeared on the board and for how long, which a club gives sponsors as evidence that a contract was delivered. A useful log records what reached the wall, including interruptions and fades to black. USM logs each item to a hundredth of a second and exports a report per fixture as PDF or Excel.How proof of play works
Virtual advertising
Virtual advertising, also called digital board replacement (DBR), replaces what the perimeter boards show in a broadcast feed with different artwork, so viewers in different countries see different sponsors on the same boards. It is done by specialist broadcast systems that track the boards in the camera picture. USM Boarding drives the physical boards and does not make replacement feeds.

Running it.

What runs the wall on a match day.

Playout
Playout is the job of sending prepared video and graphics to a display or broadcast channel at the right moment, and playout software is the program that does it. For an LED perimeter it means rendering the wall’s picture, advancing the rotation on time, taking the operator’s cues during the match and logging what ran.What LED boarding software does
CasparCG
CasparCG is an open-source server for playing out video and graphics, first developed by the Swedish broadcaster SVT and controlled over a text protocol called AMCP. It is used in television and live events for graphics and playout. USM Boarding runs a patched build of CasparCG on Windows as the engine that renders the wall.What LED boarding software does
NDI
NDI (Network Device Interface) is a protocol for sending live video and audio over an ordinary IP network with low delay, developed by NewTek and now owned by Vizrt. In a stadium it links playout, graphics and streaming machines without dedicated video cables. USM Boarding can send its output as NDI and take NDI sources in.
Main and backup PC
A main and backup PC setup runs two playout computers side by side, so the second can take over the wall if the first fails. The backup follows everything the main PC does. In USM Boarding the backup follows the main PC over the venue network and takes the wall when its heartbeat stops.The backup PC in detail
Heartbeat
A heartbeat is a short message one machine sends another at a fixed interval to show it is still running. When the messages stop, the receiver treats the sender as failed. USM’s main and backup PCs send one every second, and the backup waits about five seconds before taking over, so a machine that is briefly busy keeps the wall.The backup PC in detail
Fade to black
Fade to black (FTB) takes the whole output down to black over a short fade, used to clear the wall when something should not be on it. In USM Boarding it is on the B key and stays clickable even if the render engine stalls. The manual calls pressing it the one habit worth forming.

A word missing?

Send us the term you were looking for and we will add it.

Talk to us