Monitors
WinDisplayManager talks to your monitors over DDC/CI, the control channel built into HDMI, DisplayPort and USB-C cables. Changes go straight to the monitor’s own settings, the same ones you’d change with its on-screen menu buttons.
Before you start
Section titled “Before you start”- Enable DDC/CI on the monitor. Most monitors have a DDC/CI option in their on-screen menu (often under System, Others, or Setup). Some ship with it off.
- Direct connections work best. Docks, KVM switches, HDMI splitters and some USB-C adapters don’t pass DDC/CI through.
- Built-in laptop panels don’t support DDC/CI. They don’t appear as controllable monitors.
If no monitor responds, the app reports No monitors with DDC/CI support found.
Monitor pages
Section titled “Monitor pages”Each detected monitor gets its own entry at the top of the navigation list,
named after the monitor with its resolution, e.g. DELL U2723QE (3840x2160),
or Monitor N if Windows reports no name. The Hotkeys, Profiles and
About pages follow.
A monitor page shows:
- The monitor name, its resolution and desktop position (e.g.
3840x2160 at (0, 0)), and [Primary] for the primary display. - Input Source: the current input and a dropdown to switch.
- Brightness and Contrast: the current value against the monitor’s
own maximum (e.g.
70 / 100) and a slider.
Monitor numbers such as Monitor 2 are labels for the current session only. Hotkeys and profiles store the monitor’s full Windows device path instead, so reordering or reconnecting displays doesn’t send a command to the wrong monitor.
Brightness and contrast
Section titled “Brightness and contrast”The slider range comes from the maximum each monitor reports, which is usually 100 but not always. While you drag, the label shows (pending); the final value is sent once you stop moving the slider, so rapid changes don’t flood the monitor.
Input source
Section titled “Input source”The dropdown lists the inputs the monitor advertises in its DDC/CI capabilities. If a monitor doesn’t advertise a list, the app offers a standard set instead: HDMI 1/2, DisplayPort 1/2, and USB-C 1/2. Not every entry in that standard list will exist on your monitor.
Inputs the app doesn’t recognize are shown by their raw code, e.g.
Custom (0x42).
After switching to another input, the monitor may stop answering DDC/CI on this PC’s cable (it’s now showing a different source). That’s expected; use a hotkey or the monitor’s buttons to switch back.
Refresh and Retry
Section titled “Refresh and Retry”- Refresh (the icon at the left of the header) detects monitors again and re-reads every value. It cancels changes that are still waiting to be sent. Use it after plugging in, unplugging, or rearranging displays.
- If a monitor can’t be read at all, its page shows Monitor N unavailable, the error, and a Retry button that re-reads just that monitor.
- If only one value fails, its section shows Could not read … with the error and the label reads Unknown. Other controls keep working. The brightness or contrast slider is replaced by Refresh to adjust, because the app won’t guess the monitor’s range.
Power mode and custom VCP codes
Section titled “Power mode and custom VCP codes”The monitor page doesn’t include power controls. To put a monitor into standby or turn it off, create a hotkey with a Power Mode or Turn Off action, or use Turn Off Monitors in the tray menu (see Settings & startup). Hotkeys can also write any raw VCP code with a Custom VCP Code action.
DDC/CI codes used
Section titled “DDC/CI codes used”| Feature | VCP code |
|---|---|
| Brightness | 0x10 |
| Contrast | 0x12 |
| Input source | 0x60 |
| Power mode | 0xD6 (On 1, Standby 2, Suspend 3, Off 4) |
Standard input values: DisplayPort 1/2 0x0F/0x10, HDMI 1/2
0x11/0x12, USB-C 1/2 0x13/0x14. Many monitors use their own values;
the app uses whatever the monitor advertises.