By: Joseph D. Cornwall, CTS-D
Technology Evangelist — C2G
Technical lingo is a kind of shorthand that's used to express concepts common to that specific topic or area of study. Technical lingo is important because it provides a very precise or unique "shorthand" description of a device, effect or concept. Unfortunately, if you aren't comfortable and familiar with the lingo of a topic it can be a tall hurdle to communicate efficiently with folks who consider the jargon of their field to be "self-explanatory." In this series of articles we'll lift the veils of misunderstanding from the lingo of the A/V industry.
Consumer Electronic Control, often referred to simply as CEC, is a feature that is part of the HDMI standard. CEC is designed to allow one device to control up to 15 other connected CEC-enabled devices using an HDMI interface. For example, a Blu-ray DVD player may be able to control an attached display such as a flat panel LCD TV. CEC allows two forms of control—user initiated and device initiated.
An example of user initiated control would be pressing the volume or input selection buttons on a DVD player's remote and controlling a display as a result. It's important to understand this isn't the same as a "universal" remote control, as the controlling signals are actually traveling through the HDMI cable from the DVD player to the display. An example of device initiated control would be automatically changing the input of the attached display to "DVD" when the play button is pressed on the player. Again, the control signal is sent via the HDMI cable.
CEC is a one-wire bidirectional serial bus. One wire in an HDMI cable is designated to carry the CEC signal. The CEC system itself is based on the CENELEC standard. CENELEC is the European Committee for Electrotechnical Standardization, and was created in 1973. It is responsible for standardization in the electrotechnical engineering field. While CEC wiring is mandatory in all HDMI connections, beginning with the very first HDMI 1.0 release in 2004, the actual implementation of CEC capability is not mandatory. Each manufacturer is free to include or exclude CEC functionality in particular products.
Manufacturing companies often give proprietary names to their implementation of CEC functionality in a family of products. Trade names for CEC include Samsung's Anynet+, Sharp's Aquos Link, Sony's BRAVIA Link and BRAVIA Sync, and Panasonic's VIERA Link. Despite these copyrighted names, all of these systems are implementations of the CEC standard.
As might be expected, Consumer Electronics Control (CEC) is often not implemented on products designed expressly for the commercial market. For example, an LG commercial display may not respond to CEC commands, while the corresponding model from the consumer line does. Typically this is because the CEC functionality has the ability to be turned on or off via a menu selection on a device's service menu.
The following is a list of the most common HDMI-CEC commands:
This white paper is for informational purposes only and is subject to change without notice. C2G makes no guarantees, either expressed or implied, concerning the accuracy, completeness or reliability of the information found in this document.