Noob E1.31 protocol question

[firstone]

I'm trying to code Arduino to translate E1.31 to control RGB lights. But while I understand how E1.31 protocol itself work, I can't seem to find any information on what is that actual data that is carried in the protocol messages. My end goal is to have some software, like LightShow Pro send E1.31 messages. So what I can't seem to find is what will be actually sent in the data bytes by the software.

Or is it simply the case where the protocol is generic and I will need to program the software to send the correct data? I apologize if it sounds silly but I don't have any experience with any sequencing software yet.

If this could be answered with a search, please, point me into the right direction. I've tried to do some searches but cannot find anything relevant.

[budude]

I'm not sure if you saw the sticky posts by Ben - http://doityourselfchristmas.com/for....13-and-ArtNet)
Not sure if it helps or not...

[erm213]

You could also look at the source of the J1sys E1.31 plugin. Since it generates E1.31, you can see how the data is constructed, which helps when deconstructing!

Erik

[David_AVD]

The E1.31 packets basically contain the DMX512 data (513 bytes) as well as some extra stuff. (universe, priority, etc)

[firstone]

The E1.31 packets basically contain the DMX512 data (513 bytes) as well as some extra stuff. (universe, priority, etc)

I think I wasn't able to properly explain my question.

I understand how E1.31 works. Yes, I understand E1.31 message basically contains DMX-512 data (SC + 1 to 512 bytes). I also understand how DMX-512 protocol works. After SC, each byte represents a command to a DMX channel. All this is clear.

What I don't understand (and cannot find clear specs for) is what those commands for DMX channels really are. How does byte 0x123 translates into channel turning on or off or turning to color green, etc. Is there a set standard for those commands or is it different for different DMX devices.

Thank you for your responses. I will look through all the information again in case I missed something the first time around.

[budude]

It's just a byte stream - for a light fixture, the value sets the intensity of that particular channel within the stream. So if you set channel 14 to '0x20', the light will be dimmed to that level. It's up the the receiver to figure all that out and perform PWM or whatever to dim the light fixture(s).

[firstone]

Thanks. How would it work for RGB pixels? Would it be R, G, B then dim level? Something like that?

[Matt_Edwards]

No,
For RGB, the DMX channel value determine the intensity on each colour. thus 3 channels are required. Weather Red is the first channel or not is important but can vary from controller to controller. Your ap will need to be able to set the colour to a particular channel.

[David_AVD]

Typically, each value (byte) of the DMX data corresponds to the intensity level of a channel. Most DC controllers just map those 8 bit values as intensity of individual output channels.

A controller that accepts DMX can do whatever it likes with the data however. It may use certain values to select operating modes, drive servos, etc.

The main thing to realise is that the DMX stream doesn't itself describe what the data is destined to do. It's just a way of sending up to 512 channels (bytes) to a controller.

[firstone]

Thank you. It mostly answers my question. I certainly have more but at this point I will probably start up sequencing software and try to generate some messages rather than keep asking more questions.