iDMX / Software / E1.31 Basics

[cancolby]

Hello. I've been a LOR and iDMX user for several years. I was hoping sombody could enlighten me regarding E1.31 and the iDMX's protocol.

Does the iDMX simply run DMX data into an enthernet cable or is there a conversion of info somewhere?

Can the iDMX be used with other USB dongle lighting software like Compu Show?

And how does ArtNet fit into all this? I've been trying to learn more about these new control methods and arrangements but haven't had much luck yet.

 

Thanks!

Colby

[kiplorenzo]

Actually, the IDMX is for DMX devices. But E1.31 is also DMX but in multiple DMX universes..  E1.31 runs on the network port of the computer and outputs to the controller (Sandevices for instance)

[jerrymac]

E1.31 is a protocol for sending dmx data over Ethernet (cat 6, cat6 etc network cable).

Multiple DMX universes can be sent over the same cable.   E1.31 controllers then take this data and send the correct universe to a specific output connector in DMX data , SPI data or pixelnet data.  

Controllers can send the data in DMX (E1.31 to dmx protocol converters) like J1Sys  (4 universes) and DYI Light Express (6 universes).  This output data is regular DMX for any DMX device.  

Controllers can also convert the output data to SPI data for pixels  or strips or convert to pixel net for pixels or stips.  

This eliminates the need for a dongle.  You tell the software that it is E1.31 and the data is sent over the network connector on your computer rather than through the USB connector for a dmx dongle or crossover cable 

It is possible to mix output types (USB 485, E131 to SPI, E1.31 to pixelnet via multiple networks and or through a network switch (kind of like an electronic switcher)

(this is of course not the techno explanation but hopefully helpful (and correct enough for regular folks use ) to non techies).

Edited July 1, 2014 by jerrymac

[cancolby]

Okay, I see. So what does the LOR iDMX do? Is it essentially a one-universe E1.31 controller or is it specific to LOR's language?

 

Is a crossover cable just a USB to Cat-5 adapter, doing the same thing as a USB dongle?

[Steven]

So what does the LOR iDMX do? Is it essentially a one-universe E1.31 controller or is it specific to LOR's language?

 

The iDMX has nothing whatsoever to do with E1.31. (E1.31 is an Ethernet connection: DMX over UDP/IP on Ethernet.)

 

The iDMX is a protocol translator. It takes the LOR protocol in, and gives DMX out.

 

 

Is a crossover cable just a USB to Cat-5 adapter, doing the same thing as a USB dongle?

While both LOR and DMX use the RS485 physical (electrical) layer (with different pin-outs), they use different protocols, which is why the iDMX is much more than a crossover cable.

 

LOR is command-based, where a command (or event) is something like "turn on 50%", "fade down from 75% to 25% over the next 5 seconds", or "shimmer at 80%". This makes it bandwidth-efficient, but requires more intelligence in the controllers. DMX is level-only based, where each level is sent to ever channel about 44 times a second. To handle this translation, the iDMX has to keep track of which channels are fading or shimmering.

 

The iDMX only does LOR to DMX protocol translation. It only works on an LOR network.

[sax]

iDMX is similar to a DMX dongle. Except it is seen as another controller on the LOR network as 512 channels (1 dmx universe).

So your normal LOR AC controller is unit 1 with 16 channels. iDMX can be unit 2 with up to 512 channels.

Once you get the iDMX in the network connected then you will need to connect DMX controllers to the iDMX. There are a lot of dmx controllers out there including entire moving light units or fog machines as well as standard 3 channel controllers for RGB lights.

What the iDMX does is allow control of these devices through the LOR network and not a seperate DMX network. Especially useful if you run your shows without an attached PC.

[plasmadrive]

One thing I learned over the last few months... the iDMX is not good for over 128 channels if you plan to program with standard LOR effects such as fading, color changing, shimmering and so on.  I believe it will accept "DMX" commands from S3, but it won't do intelligent  things like fading passed the 128th channel.  It will translate a specific DMX value only above that channel.

 

It is a pretty good bulletproof way to get you from LOR network to the first 128 channels of standard effects.  Works great for that.. If you need ON/OFF type of interface, it will work OK above channel 128 for that.

[Steven]

... but it won't do intelligent  things like fading passed the 128th channel.  It will translate a specific DMX value only above that channel.

 

There may be a little confusion with that statement, which could be interpreted as saying that on an iDMX, you can do fades, etc on channels 1-128, but not on channels 129-512.

 

It actually doesn't work like that. The "128 channel" issue will come up if you are using fades (or shimmers or twinkles) on 128 iDMX channels at the same time, and then attempt to do such an effect on a 129th channel. It doesn't matter which channel numbers you are using, you can do effects on any of the 512 channels, up to 128 at the same time.

 

The way the iDMX does this is it has 128 "intelligent" spots. When you issue an "intelligent" effect (fading, shimmer, or twinkle), it will allocate one of these spots to the channel. When that effect is done, it releases that spot, freeing it for use with another effect, on another channel. In practice, most sequences will not run out of these "spots", unless you do a "whole display" effect, such as fading down 300 channels (on one iDMX) at the same time. In that case, 172 of the channels will go immediately to the ending value. Which of the 172 channels do this depends on the order in which the fade events are received by the iDMX.

[plasmadrive]

Steven,

 

Thanks for clarifying this.. I was trying to use 432 channels at one time..  That is why it worked for my application the way it did. 

 

Craig