VESA Monitor Control Command Set or MCCS is a computer standard developed by
Video Electronics Standards Association
VESA (), formally known as Video Electronics Standards Association, is an American technical standards organization for computer display standards. The organization was incorporated in California in July 1989To retrieve the information, searc ...
. It defines a binary protocol for controlling the properties of
computer monitors
A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls.
The ...
from a host device such as PC, set-top box, etc.
MCCS requires a bidirectional communication protocol like
Display Data Channel
The Display Data Channel, or DDC, is a collection of protocols for digital communication between a computer display and a graphics adapter that enable the display to communicate its supported display modes to the adapter and that enable the com ...
between host and display, although the specification does not favour any particular protocol.
Controls
A ''virtual control panel'' (VCP) code is a binary code that represents a single command entity in the MCCS language. Each command contains variable number of data parameters and command attributes.
The following groups of controls are defined in the standard:
* Factory Preset - commands for restoring factory defaults, as well as specifically restoring color, geometry, brightness/contrast, and TV settings defaults, and storing/restoring presets.
* Color Adjustment - commands that control color temperature, hue, and saturation.
* Geometry Adjustment - commands for adjusting CRT display geometry, such as parallelogram, pincushion, etc.
* Image Adjustment - various general commands such as display orientation, degauss, gamma, zoom, focus, brightness/contrast, backlight control, etc.
Three categories of controls exist:
* Continuous (C) - allow values between zero and a maximum value.
* Non-continuous (NC) - only support a limited set of values.
* Table (T) - large blocks of data.
Control data may be read and write (RW), read-only (RO), or write-only (WO).
The display exposes its supported internal controls via capability strings.
Versions
The original MCCS standard version 1 was released on September 11, 1998.
MCCS Version 2 was released on October 17, 2003. A major update of the standard, it provided support for flat panel displays, VESA DPVL (
Digital Packet Video Link Digital Packet Video Link (DPVL) is a video standard released by VESA in 2004. Unlike previous technologies, in order to save bandwidth, only portions of the screen that are modified are sent by the means of this link. DPVL also introduces metadat ...
) standard; it added a range of television controls and introduced individual control of multiple windows on a display. New classes of VCP codes associated with asset management, secondary displays (for information, status, etc.) and remote program calls to the display processor are introduced.
MCCS Version 2, Revision 1 was released on May 28, 2005 and included some minor updates, as well as clarifications and improved usability of the standard.
MCCS Version 3, released on July 27, 2006, was a major revision and update which introduced significant changes, however this revision has seen very little support from the industry.
The latest release of V2 standard is version 2.2a, adopted January 2011.
Notes
References
{{reflist
Computer display standards
VESA