HD and Beyond: Control using CEC - something to be feared no longer
By Chris Pinder and Daniel Adams, HDanywhere.
HDMI-CEC is an instantaneous protocol built into HDMI that allows devices to talk with, ...
HDMI-CEC is an instantaneous protocol built into HDMI that allows devices to talk with, and send commands to, one another over the HDMI cable. CEC was designed to enable command and control of up to fifteen CEC-enabled devices, all connected through HDMI, using just one remote. Pressing the 'play' button on a DVD remote could, for example, automatically turn on an AV receiver and switch it to the correct input, as well as turn on the TV and switch it to the right input from the AV receiver.
CEC- Standardising control commands, allowing control and one-touch commands from a single remote.
The Early Years
After being defined in HDMI Specification 1.0 and updated in HDMI 1.2, HDMI 1.2a and HDMI 1.3a, CEC was initially synonymous with unreliability. It tended to work only in situations where every system component was from the same manufacturer.
As interoperability was not mandatory, manufacturers limited CEC commands to their own products, so CEC commands were often lost in translation between system components from different manufacturers. Such unreliability proved a huge stumbling block to allowing integrators to place their trust in this feature of HDMI. Increasingly, integrators became conditioned to turn CEC off.
Time to Turn On
Integrators should really think of CEC as a better alternative to using the more outdated IR and RS232 serial signals for TV control. With the signal being transmitted over the existing HDMI cable, CEC removes the need for IR or serial cables and gets rid of the unsightly IR bud on the front of the display.
The need for IR buds on displays can be eliminated if CEC is used correctly.
When used correctly, CEC is arguably the neatest option for custom install third-party control systems and there are matrix and distribution products available that support CEC commands ready to use inside third-party control system drivers
For example, the webOS browser-accessed operating system for the HDanywhere’s Modular 4K matrices, allows integrators to tap into some of CEC's capabilities, including Device OSD Name Transfer. When integrators make use of Modular 4K's ability to change sources at a display using the TV's own remote, instead of the ambiguous 'HDMI 1' or 'AV 1' appearing, they can change it to appear as something more useful to the end-user, such as 'Sky HD box 1' or 'Sony Blu-ray Player'.
HDanywhere’s Modular 4K matrix.
Another example is Just Add Power's HD/IP 2G+ range, which transforms CEC protocol into a controlled, structured environment. While some other HDMI matrix solutions allow CEC to run wild, delivering undesired results, devices in the HD/IP 2G+ product range isolate the CEC signals, allowing the control system to decide which CEC signals to send, and where to send them. You can turn displays on/off and perform any other CEC function without IR bugs being attached to displays and sources.
When devices with CEC 2.0 installed arrive on the market with their expanded set of extensions, we will see integrators and consumers benefit alike. CEC 2.0 means that more commands to control your DVD players, media players or set-top boxes will be available from your standard TV remote.
Another key change with CEC in the HDMI 2.0 specification is the move from its voluntary inclusion to being mandatory. Remote control pass-through, audio control and standby will have to be part of any CEC 2.0 device. This standardisation means that CEC will become far less hit and miss. With manufacturers having to include such features to meet the specification, you can be fairly certain that CEC commands will become more reliable.
CEC is a technology not to be turned off all of the time. With more power and control coming as part of CEC 2.0, dealers should rethink HD distribution-based CEC. CEC is no longer to be feared by integrators, but is something that your HDMI matrix should embrace.
Chris Pinder is the founder of the HDanywhere brand of HDMI video matrices and signal management products, and MD of its parent company HD Connectivity Ltd. Daniel Adams is the Director of Technical at HDanywhere.