Editing KVM switch (section)

==Monitor==

A monitor uses [[Display Data Channel|DDC]] and [[EDID]], transmitted through specific pins, to identify itself to the system. KVM switches may have different ways of handling these data transmissions:
* None: the KVM switch lacks the circuitry to handle this data, and the monitor is not "visible" to the system. The system may assume a generic monitor is attached and defaults to safe settings. Higher resolutions and refresh rates may need to be manually unlocked through the video driver as a safety precaution. However, certain applications (especially games) that depend on retrieving DDC/EDID information will not be able to function correctly.
* Fake: the KVM switch generates its own DDC/EDID information that may or may not be appropriate for the monitor that is attached. Problems may arise if there is an inconsistency between the KVM's specifications and the monitor's, such as not being able to select desired resolutions.
* Pass-through: the KVM switch attempts to make communication between the monitor and the system transparent. However, it may fail to do so in the following ways:
** generating Hot Plug Detect (HPD) events for monitor arrival or removal upon switching, or  not passing monitor power states  - may cause the OS to re-detect the monitor and reset the resolution and refresh rate, or may cause the monitor to enter or exit power-saving mode;
** not passing or altering MCSS commands - may result in incorrect orientation of the display or improper color calibration.

Microsoft guidelines recommend that KVM switches pass unaltered any [[I²C|I<sup>2</sup>C]] traffic between the monitor and the PC hosts, and do not generate HPD events upon switching to a different port while maintaining stable non-noise signal on inactive ports.<ref name=W7DisplayGuide>{{cite web|url=http://www.microsoft.com/whdc/device/display/GraphicsGuideWin7.mspx|title=WHDC: Graphics Guide for Windows 7|publisher=Microsoft|date=2009-06-12}}</ref><ref name=W7KVMGuidelines>{{cite web|url=http://www.microsoft.com/whdc/device/display/KVM-Win7.mspx|title=WHDC: Display Guidelines for KVM Switches in Windows 7|publisher=Microsoft|date=2009-06-18}}</ref>

; Monitors with built-in KVM switch functions : More monitors had been included a built-in KVM switch to be able to have two computer systems (two upstream system connections) to share the monitor. However, since most of current monitors with KVM switch functions had been putting the only hub-class KVM switch with them. There is no HID emulation or no EDID emulation/feeding to all connected systems. In addition, they're limited to having 2 systems connected to it. And only can control one monitor (the monitor itself only) with the built-in KVM switch. The built-in KVM switch CAN not support multi-monitor switching and control via it. {{Citation_needed|date=November 2023}}