Setting the Windows output resolution for an LED sender card

How the picture reaches the band

The graphics card sends a normal video signal (HDMI, DVI or DisplayPort) to the sender card — NovaStar, Colorlight, Linsn and similar. The sender card splits that picture over its Ethernet ports, and each port feeds a chain of receiver cards inside the cabinets. Which part of the rectangle goes to which cabinet is decided once, in the sender-card software (NovaLCT, LEDVISION and others).

So the long band is folded into rows on the PC side: row 1 holds cabinets 1–15, row 2 holds 16–30, and so on. LedPlayMeter draws the band in exactly this folded layout, and the sender card unfolds it again.

Step 1 — Work out the output resolution you need

Divide the output width by the cabinet width to get the cabinets per row, and the output height by the cabinet height to get the number of rows. Their product is the largest band that output can carry. For 256 × 144 px cabinets:

Step 2 — Make the sender card announce that resolution

Windows only offers the resolutions that the connected device reports through its EDID. Most sender cards let you set this in their own software — look for a setting such as input resolution, DVI/HDMI resolution or custom resolution / EDID in the sending-card settings of NovaLCT, LEDVISION or your vendor’s tool. Set it to the value from step 1, then unplug and reconnect the video cable (or restart the PC) so Windows reads the new EDID.

If the card cannot store a custom EDID, create a custom resolution in the graphics driver instead (see step 3) or use a hardware EDID emulator between the PC and the sender.

Step 3 — Set the resolution in Windows

1. Connect the sender card to an output on the graphics card (not the motherboard) using HDMI 2.0 or DisplayPort 1.2 or newer — both carry 3840 × 2160 at 60 Hz.
2. Open Settings → System → Display and click Identify to see which number is the sender card.
3. Choose Extend these displays. Never use Duplicate: the operator screen and the LED output must be separate.
4. Select the sender-card display and set Display resolution to the value from step 1.
5. Set Scale to 100%. Any other value enlarges the picture and one image pixel no longer equals one LED pixel.
6. Under Advanced display, set the refresh rate to 60 Hz — or 50 Hz where broadcasts run at 50 Hz, so TV cameras do not show flicker.
7. If the resolution is not listed, create it in the driver: NVIDIA Control Panel → Display → Change resolution → Customize → Create Custom Resolution; AMD Software → Settings → Display → Custom Resolutions; Intel Graphics Command Center → Display → Custom. Test it before saving.
8. Turn off everything that alters the picture: HDR, Night light, driver sharpening or “enhancement”, and set the colour range to Full (0–255) — limited range turns black into grey on LED.
9. Set sleep and screen-off to Never and disable the screen saver.

Step 4 — Match it in LedPlayMeter

• In Field Template, enter the cabinet width and height, and the edges of the field with their cabinet counts. The total band size is calculated for you.
• Under Render resolution, set Cabinets per row to the number from step 1 (15 for a 3840-wide output with 256 px cabinets) and press Auto-calculate. The render width and height must not exceed the Windows resolution.
• The Player output map table lists the pixel range of every edge — this is the list you copy into the sender-card software.
• Open the player full screen on the sender-card display, then press Start module order test: every cabinet shows its own number.

Step 5 — Map the picture in the sender-card software

In the screen or connection configuration of NovaLCT, LEDVISION or your vendor’s tool, place the receiver cards row by row at the X/Y positions from the player output map. Then check the module order test on the real band: the numbers must run 1, 2, 3 … along the pitch without gaps, repeats or jumps. A wrong number means a wiring or mapping error — fix it now, not on match day.

Troubleshooting

• Picture shifted, cut off or repeated — Windows scaling is not 100%, or the Windows resolution differs from the one the mapping was made for.
• Soft or blurry edges — the graphics driver is scaling the picture. Use the native EDID resolution and set scaling to “No scaling”.
• Grey blacks, washed-out colours — colour range is Limited; set it to Full.
• Flicker or bands on TV cameras — refresh rate does not match the broadcast; try 50 Hz and check the refresh setting of the receiver cards.
• Resolution resets after a restart — the sender card is not storing the EDID, or the cable was connected after Windows started. Save the EDID in the sender software or use an EDID emulator.
• The sender display is missing — cable or port problem; try another port on the graphics card and a certified cable.