oksidizer USB2DMX

[IanS]

Hi
I'm pretty new to Freestyler, and it's taking a while to find my way around, so excuse me if my questions are dumb or have been raised before!

Does anyone have experience of using the Oksidizer USB interface (published in Elektor magazine)?
I have built a version of this (modified slightly to give two optoisolated outputs, but using the standard software code)
It works fine most of the time, but occasionally stops responding to Freestyler commands. The indications from the interface are that it is receiving no DMX data. Neither reseting the Freestyler interface (setup > Freestyler setup > Reset Output), stopping/removing and reconnecting the USB dongle, or closing and restarting Freestyler will bring it back to life. The only way I have found is to close Freestyler, stop the USB device, disconnect and reconnect the USB, then restart Freestyler.
I'm unsure if this is a problem with my interface, or something that is disturbing Freestyler, but would appreciate any comments. Oh, I'm using Windows XP.

Thanks in advance

Ian

[dmxlighting]

Hi Ian

I get this problem from time to time.
If I am using it over a 4 to 5 hour job I would expect it to crash (like you said) once and have to shut down and restart FS.
I dont have to unplug my interface though! (using Enttec Pro).
It maybe your interface, ive not got any knowledge of it myself but its listed in the setup so must be known to some people.

[lj_raph]

Hi

On the internet look for "Disable Selective Suspend" feature.
There should be a patch from Microsoft somewhere to fix this.

If you can't find it you can achieve the same thing if you disable usb power saving on your USB root hub (Device manager)

[yofo]

a friend made me a "Oksidizer USB interface" out of that magazine, and this is my first experience with DMX and I'm buring up my space laser,3 with frestyler, I've made a 160 step cue, extream manipulation of patterns, and so on, I'm not giving huge problems.

[yofo]

man, I kinda have the same problem with my oksidizer dmx controller, homemade also by n friend

there is my thread, check to see if you have the same problems
http://www.freestylersupport.com/fsforu ... f=6&t=1972

[dmxlighting]

Yofo,

I really think that you may need to get yourself a different device. See if you can borrow one from someone just to see if the problems you are having go away.

[yofo]

that will be cool, but I have some problems with that one, I'm in South Africa, I'm probably the only one who bother with DMX in my country, unless the people of does this stuff in the bigger cities for a living, so I don't have that much resources to use, I have found my homemade DMX controller by talking with someone on a local forums website.

[yofo]

ok, my oksidizer USB2DMX looks very stable now,.
I can go crazy with it, just dont unplug the USB, because then it will freeze
"for example, I can unplug the DMX cable from my laser and plug it back without making my laser and/or Freesyler to freeze out of me"

here is how to fix it:

#1
by IanS
The key was the power save feature that the USB driver has,
disabling this did seem to fix the problem. If you use Windows Device
Manager, and navigate to USB Controllers, then under each occurrence of USB
Root Hub, there is a Power Management Tab. Disable the check box for "Allow
the computer to turn off this device to save power".
Since I did this, I haven't had any further problem. I have recently
migrated my DMX controller to a new PC, and I disabled this Power Saving
from the start, and again it runs without problems

#2
and another option that I used that might also make it more stable.
the use of a Ferrite core clip on on the USB cable that go into the DMX controller.
It's general use is to filter out spikes that can cause sensitive hardware to freeze or none respond, the spikes can occur from for example, a air-conditioner or a messed up power switch and so on....., so assume it's a low level EMP pulse that get's released from certain appliances
look in my attach files for example, of what I used

#3
the use of a terminator with a 100 Ohm resistor on pin2 and pin3


#2 and #3 is probably not so important, but just do it. You dont want your dmx controller to freeze in FS, then your doing a live light show

[Shannon D]

Yofo,
Glad to hear you got it going. It must be tuff not having all the resources. Your persistance paid off. Good job man!

[yofo]

thx

[yofo]

yo people, I have a oksidizer USB DMX512 adapter and it's still giving me troubles, I last problem I've sorted out was to connected the shield problem, because my adapter wasn't properly "grounded" so it kept on freezing up for some random reasons like for example, then you turn on a fan.

now my problem is, then I operate my dmx laser "it's a JB system, space laser 3" the one with black paint on it "8ch" ok then I operate it, it works fine but but while I use it I turn off the power of the laser, and then If I turn the power back on, it freezes my whole dmx system, If I want to fix it, I have to unplug everything, by everything I mean, both plugs on dmx adapter, usb and dmx out, but before that I have to power down the laser, and then plug it all out and plug it back again, and then after that is done I can switch on the dmx laser, and then it works fine, is this normal that it freezes?

[yofo]

When you say turn off the power on the laser, do you mean physically switch it off or do you mean you select a DMX channel/value which does a turn off.

physically switch it off

[yofo]

Also if you are using the Fixture file from this forum it does not match what is in the manual, so most probably will not work correct at all.

I made my own fixture, all functions work 100%, it was just weird that it freezes up the I physically switch it off and then back on, is there anything I must be on the look out, that you know about, I don't think that it can be my made fixture that have a problem, but I not the programmer, so I won't know for a fact

[yofo]

When you say turn off the power on the laser, do you mean physically switch it off or do you mean you select a DMX channel/value which does a turn off.

physically switch it off

I would say you are getting spikes from your electric circuits causing the DMX unit to freeze. Maybe you need filtered and/or surge protection somewhere in you power supply to your computer and/or fixtures.

This interface is not opto-isolated so maybe you should use a DMX splitter to stop dodgy signals coming back to the interface.

Turning off fixtures and back on is the only way you can get some fixtures to work if they are not working first time around. I have a few LED Par Cans that sometimes do not detect the DMX signal after they have been switched on for the first time so I have to switch off/on to get them back.
If I was getting what you was getting I would either throw the fixtures away or the DMX-USB interface.

See if you can borrow or hire a proper DMX interface (obviously one that works in FreeStyler) to see if that has problems. Get one that is opto-isolated or get a DMX splitter as well.

Other than that I do not think we are going to be able to help you resolve this issue.

yea I also thought that it spikes and noise that freezes up the, but I fixed that problem by hooking up the shield wire pin on the xlr from my dmx adapter, dmx out to my usb shield in the adapter and grounding it a while ago, and now it's more stable and doesn't just go of then I make a spike by mistake, by turning on a aircon or fan or something that makes a spike, even a smoke machine makes a spike, everything seems to makes spikes, lol

I don't think I'll be able to get a dmx adapter from a friend, because I don't such friends, I'm a amateur LJ, in experimental stage with my stuff.

isn't the oksidizer USB2DMX opto-isolated ?

[yofo]

I also starts to think that it might be a opto-isolator that might be needed, but the $1 million question is, why does dmx adapter freezes up then I physically switch the laser off power and then back on... can the oksidizer USB2DMX really freezes, because of that, it's just mind bobbling to me, maybe I have a cheap laser that is messed up? and why does the oksidizer USB2DMX care what signal it's getting back? isn't it a fire at will, and don't care about the commands it fires down the dmx line, just like a UDP protocol on a network

[yofo]

I also starts to think that it might be a opto-isolator that might be needed, but the $1 million question is, why does dmx adapter freezes up then I physically switch the laser off power and then back on... can the oksidizer USB2DMX really freezes, because of that, it's just mind bobbling to me, maybe I have a cheap laser that is messed up? and why does the oksidizer USB2DMX care what signal it's getting back? isn't it a fire at will, and don't care about the commands it fires down the dmx line, just like a UDP protocol on a network

yes it does not care it just sends DMX signals out. Should not get anything back (another reason for a terminator) and if your laser is causing a power spike the DMX chain might be picking it up which is then getting to the DMX interface and bingo, you have a freeze.

I have a terminator tho, it have a 100 Ohms resistor I think, or 120 Ohms, not sure at this moment

just checked, its a 100 Ohms, and it's on pin2 and pin3, correct?

[LJ_krede.dk]

I have a terminator tho, it have a 100 Ohms resistor I think, or 120 Ohms, not sure at this moment

just checked, its a 100 Ohms, and it's on pin2 and pin3, correct?

http://www.thedmxwiki.com/definitions/dmx_terminator

[yofo]

nice one, do you think that a 100 Ohms will not work that good as a 120 Ohms resistor? To me a 100 Ohms will terminate more noise, because it have a lower resistance, in my laser's manual it say's that the users needs a terminator of 100 or 120 Ohms arose pin 2 and pin 3

[LJ_krede.dk]

nice one, do you think that a 100 Ohms will not work that good as a 120 Ohms resistor? To me a 100 Ohms will terminate more noise, because it have a lower resistance, in my laser's manual it say's that the users needs a terminator of 100 or 120 Ohms arose pin 2 and pin 3

DMX (data) cables usually have a characteristic impedance at 120 Ohm, some cables more or less. the smaller diference there is between the characteristic impedance and the terminator, the more noise/reflections will be reduced. so check you cables to see what characteristic impedance.

i'm not sure on this but 100 Ohm should work ok.

but i'm not an expert and don't want to "push stuff down into your throat that may not be 100 % correct"

[yofo]

My cables are high quality DMX cables, and cost a fortune , how do I check the impedance on my cables?

[LJ_krede.dk]

My cables are high quality DMX cables, and cost a fortune , how do I check the impedance on my cables?

should be written on the cables

[yofo]

My cables are high quality DMX cables, and cost a fortune , how do I check the impedance on my cables?

should be written on the cables

hehe, I also thought it might stand there, but it doesn't, It only says "EWI professional aes/ebu & DMX cable-301"

[remco_k]

nice one, do you think that a 100 Ohms will not work that good as a 120 Ohms resistor? To me a 100 Ohms will terminate more noise, because it have a lower resistance, in my laser's manual it say's that the users needs a terminator of 100 or 120 Ohms arose pin 2 and pin 3

Looking at it that way, then shorting pins 2 and 3 is far out the best way to terminate just about anything that is capable of disturbing the DMX signal. There will be one small problem though. You should be able to guess what that is.

A 100 Ohm terminator is better than no terminator. But a 120 Ohm terminator is better (the best) then an 100 Ohm terminator.
If you notice the difference, I can't tell.

You can't 'measure' the impedance of your DMX cable with regular measurement instruments. You'll need very expensive tools for that. So you might want to look up the cable brand and model somewhere to see if it has an impedance of 120 Ohms.

But still, looking at you problems, suppose you have had 120 Ohm impedance cabling and a 120 Ohm terminator. I don't think that it solves this problem. My guess is that your USB DMX interface is a littlebit 'sensitive' for interference and just 'dies' instantly. Some guys mount capacitors somewhere in the interface to eliminate such interference. (See what they do to the Enttec open interfaces - they have a lock up problem as well).

[yofo]

Looking at it that way, then shorting pins 2 and 3 is far out the best way to terminate just about anything that is capable of disturbing the DMX signal. There will be one small problem though. You should be able to guess what that is.

hehe, that should make me end up with a damage or blown chip

Some guys mount capacitors somewhere in the interface to eliminate such interference. (See what they do to the Enttec open interfaces - they have a lock up problem as well).

interesting, to my knowledge, using caps will corrupt the data, by messing with the signals, keeping it to long on, but those value are so low "47pF capacitors", it might work, but why does my adapter lock up then I turn on my laser, that's really annoying, I'm starting to think my USB locks up then my laser get turned on, somehow it's sends a spike from the laser via DMX cable to DMX adapter and then into USB and then it gets angry, and locks up, but they does a dmx device "my laser" sends out a spike then it gets turned on, that not cool, and USB is sensitive, I have had troubles with my USB devices for ever, it first started then I used usb webcams for cctv, it keep on freezing up then I turn on anything that works with a motor, or induction setup, lol, but that was replaced a couple of weeks later with the real deal, and a capture card, but this is just for interest sake, how sensitive usb is

[remco_k]

interesting, to my knowledge, using caps will corrupt the data

They corrupt signals (or 'data' if you like) when you use the wrong values connected the wrong way.
So if you don't use a 47 pF cap or you connect it the wrong way, yes, then the DMX signal which consists of really high frequencies (~250 kHz) wil be destroyed big time.
Connect the 47 pF good and the DMX signal is about the only signal that gets passed... Other shit (like a power spike or DC) is blocked mostly, preventing the interface to go down.

and USB is sensitive, I have had troubles with my USB devices for ever, it first started then I used usb webcams for cctv, it keep on freezing up then I turn on anything that works with a motor, or induction setup, lol, but that was replaced a couple of weeks later with the real deal, and a capture card, but this is just for interest sake, how sensitive usb is

Reading this I hope you have thought of immediately testing your DMX interface + rig on another computer?
If not; do so!
Its not normal for any USB interface to go down every time an electric device does something bad, that makes me think the USB interface (or build in filtering (thats with caps also)) is faulty.