What is the use of CEC

What is HDMI CEC used for?

Not only image and sound signals can be transmitted via HDMI, but also a lot of other data. The devices exchange various data and commands via it. CEC (Consumer Electronics Control) also uses an HDMI connection. The aim of CEC is that you can control important functions of the connected devices with the TV remote control. This makes it easier to use. To do this, the connected HDMI devices must support CEC. CEC is specified for a maximum of 15 devices and one television. CEC is limited to 10 devices by some manufacturers. The support of the protocol can be very different, there are different commands. The most important are:

  • Volume control, especially when using the Audio Return Channel (ARC)
  • Transfer of device names
  • Automatic switch-on of connected devices
  • One Touch Play (automatic switching to source and playback start)
  • Automatic switching to active source
  • Playback controls (forward / backward, pause, play)
  • System standby (all devices in standby at the same time)
  • Timer control of recording devices
  • Many functions can often be configured; have a look at the menu and manual of your television

If, for example, you insert a Blu-ray disc into the player and start playback, the television and sound system should switch on automatically and switch to the correct HDMI input. This usually works very well with devices from the same manufacturer and similar years of construction. If the implementation of CEC differs too much, functions will be omitted. The manufacturers call CEC differently. On the one hand for marketing reasons, but also to differentiate yourself from the functions of other manufacturers.

SurnameManufacturer
Anynet +Samsung
Aquos linkSharp
Bravia LinkSony
Digi LinkGrundig
EZ-LinkPhilips
Regza LinkToshiba
SimplinkLG
TechniLinkTechniSat
VieraLinkPanasonic

In the case of HDMI handshake during switch-on or connection, the television exchanges information with the other HDMI devices about which functions are supported and assigns addresses for communication. This also works when devices are switched off and connected via HDMI. When the CEC is active, the HDMI sources report to the television by name. This exchange takes place via pin 13 of the HDMI connection.

restrictions

Because CEC provides a television as a central element, it does not work reliably in other configurations - for example without a television (when listening to music) or with 2 TVs. Therefore, HDMI splitters usually do not support control via HDMI CEC. Because the system is not designed for 2 or more televisions. The television cannot address 2 sound systems, but only one. Because this can lead to malfunctions, HDMI CEC can be switched off on the television.

A display port connection is becoming more and more common on monitors and PC graphics cards. This connection can also be used for HDMI with a simple adapter, but does not transmit CEC control. So you cannot use CEC with a Displayport.