Forced Versus Connected Targets
This section applies only to Windows 7 and later, and Windows Server 2008 R2 and later versions of Windows operating system.
The CCD APIs introduce the concepts of connected monitors and forceable targets. A monitor is connected to a target if the GPU can detect the presence of the monitor, which is a physical attribute of the monitor and target. A target is forceable if the GPU can send a display signal out of the target even if the GPU cannot detect a connected monitor. All analog target types are considered forceable, and all digital targets are not considered forceable. The following table describes the combination of connected and forced states when the path is active and not active.
| Path-active state | Path-forced state | Monitor-connection state | Result |
|---|---|---|---|
Active |
Forced |
Connected |
Target output is enabled because a monitor is connected and is active. |
Active |
Forced |
Not connected |
Target output is enabled as the path is being forced and is active. |
Active |
Not forced |
Connected |
Target output is enabled because a monitor is connected and is active. |
Active |
Not forced |
Not connected |
The path cannot be set because it is not being forced and the monitor is not connected. |
Not active |
Forced |
Connected |
Target output can be enabled because it is being forced and a monitor is connected. |
Not active |
Forced |
Not connected |
Target output can be enabled because it is being forced. |
Not active |
Not forced |
Connected |
Target output can be enabled because a monitor is connected. |
Not active |
Not forced |
Not connected |
Target output cannot be enabled because a monitor is not connected and the path is not being forced. |
The following table describes several types of possible forced state for each path.
| Forced state | Meaning |
|---|---|
Normal force |
This forced state is lost after power transitions, reboots, or forced state is turned off. |
Path-persistent |
This forced state is lost after reboot. The Microsoft Win32 ChangeDisplaySettingsEx function always destroys all path-persisted monitors even if those monitors in their paths are the target of the ChangeDisplaySettingsEx call. If a caller calls the SetDisplayConfig CCD function with the SDC_USE_SUPPLIED_DISPLAY_CONFIG or SDC_TOPOLOGY_SUPPLIED flag set in the Flags parameter, SetDisplayConfig removes the path-persisted monitor if the new topology does not include the path that the monitor is in. For all other SDC_TOPOLOGY_XXX flags that the caller specifies in the Flags parameter, SetDisplayConfig removes the path-persisted monitor unless the caller also specifies the SDC_PATH_PERSIST_IF_REQUIRED flag and the path is active in the new topology. |
Boot persistent |
This forced state is only lost when it is turned off. This state is persistent across system reboots. |