DMX and the Helix

[Warlock]

Has anyone gotten dmx to work with the Helix and if so how did you set it up to work with Vixen ??? Also how many daughter boards are you controlling with it etc ???
Thanks a lot
Joe..

[mikentn]

Joe,

You may want to contact the developer directly with this question, as I don't think there are a whole lot of Helix users yet. I'll pm you his email addy - don't want a spambot picking up on it.

Mike

[gmbartlett]

Has anyone gotten dmx to work with the Helix and if so how did you set it up to work with Vixen ??? Also how many daughter boards are you controlling with it etc ???
Thanks a lot
Joe..

Hi Joe,

I've been able to drive two of RPM's DMX SSRs, a 4-Ch and 16-Ch. I set the address of the 4-Ch to 1 and the 16-Ch to 497. I then drove them with a 512 channel test sequence. For my test sequences I have generated a 5 minute MP3 encoded at 128kbps that outputs a 120 beat per minute metronome. The Vixen Sequence turns all of the channels on full with the first beat and fades them out. The second beat turns on the second channel then fades. The third and fourth beats do the same with the third and fourth channels. It then repeats. For the 512 channel test I only had the sequence control Channels 1-4 and 509-512. I believe this is a valid test since DMX is a serial protocol and the Helix has to transmit all of the data in between even if they are all zeros. Using this test it is easy to see if the Helix maintains timing and it is able to run this test flawlessly.

The next test I did ran the same sequence through all three Helix Channel Banks at the same time. In effect running three DMX universes all at once. I still only have two DMX boards but I moved them between the three Channel Banks to make sure each one was working properly. Again, no problems.

I did the same tests using a couple of LoR boards I borrowed from a friend. (I know friends don't let friends use LoR. The good news is he's switching to Helix this year and will still be able to use his old LoRs while increasing his channel count for less than half the cost).

You don't do anything special with Vixen to run DMX on the Helix. You use the Helix Network Supervisor (HNS) application to specify how each Helix Channel Bank is to be configured. Each channel bank can be configured to drive Helix Daughter Boards, Renards or DMX. You also use the HNS to map the channels in the Vixen sequence to the Helix Channel Bank you want to use.

As far as how many daughter boards it will control is limited by the RS485 protocol. The RS485 chip is rated to drive 32 RS485 receivers. If you plan to use Renards with DMX this won't be an issue because they regenerate the signal each time. However, with true DMX devices you will be limited to 32. I haven't been able to test this since I don't have 32 DMX devices but the RS485 driver's datasheet says it will work.

Please let me know if you have any other questions,

[blantrip]

Greg,

I know the Helix supports DMX, but I'm not sure which protocol. If I use an RS-485/RS-422 To Ethernet TCP/IP Serial Device Server, do you think it will support E1.31, streaming DMX over Ethernet, multicast format? I'm considering getting an E681 from SanDevices and the E681 does not support the unicast E1.31 protocol.

I like the idea of RGB pixels and thought since I don't have a lot of LEDs yet, this might be the way to go. Why take the easy road, I guess I like to make things as difficult as possible.

Do any other Helix owners have any DMX experience?

Bryan

[gmbartlett]

Greg,

I know the Helix supports DMX, but I'm not sure which protocol. If I use an RS-485/RS-422 To Ethernet TCP/IP Serial Device Server, do you think it will support E1.31, streaming DMX over Ethernet, multicast format? I'm considering getting an E681 from SanDevices and the E681 does not support the unicast E1.31 protocol.

I like the idea of RGB pixels and thought since I don't have a lot of LEDs yet, this might be the way to go. Why take the easy road, I guess I like to make things as difficult as possible.

Do any other Helix owners have any DMX experience?

Bryan

Bryan,

The Helix talks DMX512A, RS-485 voltage levels, 250 kbps, 1-8-2-N format on Channel Banks 2, 3 and 4. I'm not familiar with the E1.31 so I can't say for sure but since it is Ethernet I would expect it to need a much higher data rate, probably in the 1-10 Mbps range. I've looked at the possibility of driving RJ's LED Pixels which requires a 1 Mbps data rate. I think it can be done but only on a Helix Network Node. There is too much going on with playing the MP3 and keeping the timing to do it on the Helix Network Controller. That being said, I haven't actually done any testing to see if it possible to do these types of data rates. If you have any links to a good primer on E1.31 Multicast format I would be happy to take a look at it and give you a better answer.

[DynamoBen]

Greg, my PropController project has prop code for sACN (E1.31) you are welcome to use it/customize it for the Helix. Below is a complete project that uses it. At some point I need to break sACN out into its own object.

http://code.google.com/p/propcontrol...ects%2FETH_128

[blantrip]

Greg,

I saw a thread titled E1.31 Protocol Discussions if that helps at all.

It sounds like it won't work "out of the box", but I'll have to get more intelligent on this subject and also see what other DMX options are available. Ultimately I'm hoping to either use the GE Lightshow pixels or some of the other options out there.

But I should stop day dreaming and stay on task for this years show (1st one).

Thanks for the help.

Bryan

[Warlock]

The limits I see so far with the Helix and DMX to use it with the rgb pixelnet lights 128 node is simply the network supervisor software.It will only allow you to program up to 1 universe so I'm not sure if a: the Helix can only push that much data as it is my understanding that with dmx it simply pushes it out to something that can understand it or an I wrong ??? or b: that the software was only designed to push the data of 1 universe of dmx data and this can be changed so the Helix can be used along with RJ's design of the smart string controller to run the 128 node pixels..Please correct me if I'm wrong..

[gmbartlett]

The limits I see so far with the Helix and DMX to use it with the rgb pixelnet lights 128 node is simply the network supervisor software.It will only allow you to program up to 1 universe so I'm not sure if a: the Helix can only push that much data as it is my understanding that with dmx it simply pushes it out to something that can understand it or an I wrong ??? or b: that the software was only designed to push the data of 1 universe of dmx data and this can be changed so the Helix can be used along with RJ's design of the smart string controller to run the 128 node pixels..Please correct me if I'm wrong..

I'm very sorry for taking so long to get back to you on this. I received your email but then got busy with some personal and work stuff and it just slipped through the crack. I'm glad you posted it here as a reminder.

The biggest problem with using the Helix to drive RJ's pixelnet is the protocol itself. DMX is 250kbps with 512 channels. RJ's pixelnet uses 1Mbps with 4096 channels. I've looked at my DMX driver and I think I can make it work at 1Mbps but the 4096 channels is a problem. To do it correctly I would need 8K bytes just for the buffers; 4KB to transmit out and another 4KB to preload for the next event. I don't have that much free memory available in the current version of the firmware. In fact I barely have 4KB left and there are several more improvements that I still want to add.

So the short answer is that I think it can be done but it will require a custom firmware. I don't have any of the pixelnets so it would be difficult for me to write and test the code. So unfortunately it is just not feasible at this time. Maybe at some point in the future.

[hollandlihjtdisplay]

On diylightanimation.com there was someone with the same question. Hey Greg there is some of the members that comes to the mini that might be able to provide you with the smart string controller and smart strings.