# Use Display Control

Display Control sends a command from a Linux Player to a compatible display. The available controls depend on capabilities the Player reports; an online Player does not guarantee that the connected screen accepts every command.

## Control one display

1. Open **Screens** > **Fleet**, select a Linux screen, then open **Device**.
2. Select **Probe display capabilities** to refresh the reported controls.
3. Use an available action: **Power on display**, **Power off display**, **Set display input**, **Set display volume**, **Mute display**, **Unmute display**, or **Set display brightness**.
4. Check the displayed command result and the screen's last reported display state.

The current stable Electron Linux Player uses HDMI-CEC for power and input and DDC/CI for brightness and volume through its existing providers. That Player needs `cec-ctl` for HDMI-CEC or `ddcutil` for DDC/CI, access to the connected device, and a compatible display or adapter.

The Tilecast Edge M9 preview talks to Linux CEC and I²C/DDC devices directly instead of using those command-line providers. Edge can also check for DDC/CI mute when the display supports it. This is still preview behavior, so keep `cec-ctl` and `ddcutil` on current Linux Player installations that need them.

Android Players do not provide Display Control.

## Apply a group action

Open a Display Group and select **Display Control**. Review the capability counts, choose **Power on all**, **Power off all**, **Mute all**, or **Unmute all**, then select **Send to supported displays**. Tilecast sends the action only to screens that report the required capability. Offline screens may receive a queued command after they reconnect, before it expires.

The group page offers Mute actions, but the current stable Linux providers do not report mute capability. The Edge M9 preview can report mute only when the connected display exposes the corresponding DDC/CI feature. A screen without a reported capability is listed as unsupported.

## Understand the result

Tilecast can confirm that it sent or queued a command. It cannot confirm that a TV or monitor physically changed state unless the display reports that state. A command marked **sent, not confirmed** is not proof that the panel turned on, changed input, or changed brightness.

Display power and Player connectivity are separate. A Player may remain online while its display is off. Schedules can target display actions on Linux screens; Android screens and groups that include Android Players cannot receive scheduled display actions.

## Next steps

- Check [screen status](../../operations/screen-status/) when a display or Player appears offline.
- Use a [Schedule](../../schedules/) for a supported display action at a set time.