Control and integration

CEC

Consumer Electronics Control

CEC is the reason one remote can turn everything on, and on the Diva it is also the reason ARC audio does or does not appear. A single dropdown decides both.

CEC stands for Consumer Electronics Control. It is a single wire, low speed, bidirectional bus carried on pin 13 of every HDMI cable, present since HDMI 1.0 and considerably extended in 1.3a. Each device on it takes a logical address according to the kind of device it claims to be, and a physical address derived from where it sits in the HDMI tree, so a message can be sent to the television, to the audio system, or broadcast to everything at once.

What it carries is commands rather than content: one touch play, standby, source switching, remote control passthrough and system audio control. Manufacturers rename it, so the same bus appears as Anynet+, Bravia Sync, SimpLink or Viera Link depending on the badge on the front. System audio control is the part that matters most in a cinema, because it is what negotiates ARC.

CEC on the HDfury Diva

The CEC/RS232 section holds all of it. ENABLE CEC has to be checked before any dropdown below it is applied to the unit, which over IP is set cec on. Once it is on, the Diva answers and processes CEC requests and appears on the television CEC network map like any other device. The same switch, along with CEC LA, is also in the OLED menu, so it can be changed without a browser. SEND CEC TEST COMMAND puts a hex command of your choice on the bus, which is how you prove a piece of automation before building anything around it.

The device type is the consequential choice. Video Processor is the default, logical address 0x0E, and it is what you pick when you have an AVR and want that AVR to be the device using ARC and CEC. Audio Processor, logical address 0x05, turns the Diva ARC feature on, so sound from the television ARC comes back into the unit and leaves again on the HDMI audio output, the 5.1 optical output or the analog stereo jack. The IP command is set cecla audio.

The routing rule that follows from it

CEC and ARC master is always TX0. The television you want audio back from belongs on TX0, whichever display you consider primary, leaving TX1 for a second or older 1080p SDR sink. If ARC audio never appears, the CEC device type is the first thing to check, followed by Enable DD+/ATMOS ARC when your AVR can accept more than Dolby Digital or DTS.

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