ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2]  All   Go Down

Author Topic: Wireless DMX Latency - should I dump wireless?  (Read 774 times)

Bob Faulkner

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1156
  • Raleigh, NC
Re: Wireless DMX Latency - should I dump wireless?
« Reply #10 on: June 17, 2021, 08:31:52 PM »

Is there any chance that any of the fixtures have some type of delay/fade built-in to them? Some of our old Blizzard HotBoxes had a setting that made it seem like there was latency... It wasn't immediately obvious, but once we corrected the setting on the fixtures, things were more responsive.

And more power/good-on-ya to Mark for getting the Donner stuff to behave... mine always seemed to drop connectivity/fail about 3-4 minutes before showtime. I eventually moved over the the SHoWBaby stuff and it was a massive stress reducer.
Good thought.  I don't see anything.  For these fixtures, looks like everything with the fixture is "disabled" once it is connected to a DMX controller.  A lot can be set on the fixture if they are not attached to a controller.

DMX is a relatively simple and very forgiving protocol.  Simplified way that DMX works is that it sends out serial data, sending out DMX addresses in order with their values in a loop.  When a device sees it's DMX value, it listens and responds accordingly.  If for whatever reason, the fixture doesn't hear it's address in the string, it just waits until the next loop comes around and responds then.  So, in the event that there is data loss, the light still will eventually respond.

A couple of things that will cause delays. 1. The speed of re-broadcasting data.  Since data is sent in a serial fashion at a predetermined rate, the more addresses used will mean a longer time between repeating the loop.  Some devices will only broadcast addresses up to the highest address in use.  Eg, if you use 10 addresses, it sends the value for those 10, then repeats.  Other devices will send all 512 channels on each loop. This means that the response time would be slightly lower.

In the event that there is data loss, it can take time for the loop to get around again and re-broadcast the signal.  Using wireless hops that are un-responsive typically means there is data loss or corruption in the signal. Not enough to completely break things, but enough that it's only hearing the signal some of the time, thus giving you the perceived delay you are experiencing.

Good info.  Thanks for the re-broadcast info.  My 2-tree setup is only using 22 addresses.  The fixtures work great without wireless.  I'm thinking the wireless units are crap.

Something else I just thought of that I encountered with my own fixtures, If they have selectable diming curves and they are not all set to the same one that can make some of them look like they are slow to respond.
I think my fixtures have that control, but is only available if they are not on a DMX controller.

I'll continue to maintain my opinion that wireless DMX should only be used when absolutely necessary - not as a matter of convenience.  I'm all for minimizing time and effort when setting up a rig, but wired reliability isn't something I'll give up unless I have no other choice. 

That being said, when I must use it, I implement a truck and branch philosophy (console to splitter and then branch out the wired runs with the wireless transmitter on its own splitter output).  I never go from console to fixtures to transmitter to more fixtures - way too many opportunities for compromised signal to hit the transmitter and glitch everything downstream.  If you decide to keep wireless I'd suggest getting a basic splitter and using a branch for wireless only.  I can't guarantee that will fix your problem completely but it certainly won't hurt.  Good luck!

Thanks!  Yep, my use of wireless is for convenience and speed of setup.

Wireless DMX has gotten a LOT more reliable.  Even the cheapie eBay units have been extremely reliable for me.  The key is having realistic expectations.  No, you aren't going to run 500 feet through walls and expect a reliable signal!  But, for a simple LED tree, they are awesome.

Yes, I agree with you in putting the transmitter first in line.  Segmenting DMX runs makes life a heck of a lot easier when it comes down to troubleshooting problems. DMX splitters are cheap enough these days to easily implement them into your designs.

The neat thing too about wireless DMX is that it's a splitter in itself. You can have one transmitter and as many receivers as you want.  For my portable rigs, I have a receiver on each tree or truss segment and one main transmitter at the console.  Way less wires and each segment is completely isolated. If there's a problem, very easy to track down.
hmmm... did not think of using one transmitter with multiple receivers.  I have 4 wireless units; I'll try setting up one transmitter with a receiver on each tree (like you have done).

Logged

Paul G. OBrien

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1191
Re: Wireless DMX Latency - should I dump wireless?
« Reply #11 on: June 17, 2021, 09:45:33 PM »

did not think of using one transmitter with multiple receivers.  I have 4 wireless units; I'll try setting up one transmitter with a receiver on each tree (like you have done).
Oh... I missed the fact you had a wireless X-mtr daisy chained in system in your original post.. yeah that won't work well at all.
Put a reciever on each tree, and the transmitter can plug directly into the console but I find it helps to elevate it overhead in crowded venues.. it's the line of sight is best for wireless communications thing.
Logged

Bob Faulkner

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1156
  • Raleigh, NC
Re: Wireless DMX Latency - should I dump wireless?
« Reply #12 on: June 18, 2021, 08:35:33 PM »

Oh... I missed the fact you had a wireless X-mtr daisy chained in system in your original post.. yeah that won't work well at all.
Put a reciever on each tree, and the transmitter can plug directly into the console but I find it helps to elevate it overhead in crowded venues.. it's the line of sight is best for wireless communications thing.
Good points. Thank you Paul. 
Logged

ProSoundWeb Community

Re: Wireless DMX Latency - should I dump wireless?
« Reply #12 on: June 18, 2021, 08:35:33 PM »


Pages: 1 [2]  All   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.058 seconds with 19 queries.