Support Forum

Hi Guys,

I've got the enttec open USB DMX interface. Is there anyway to slow down the rate at which DMX is transmitted? It's currently too fast for my scans to 'see' so they are not working properly.

Basically - Can it be done or is there anything I can do to slow it down?


Cheers!



Tom

[Deleted by user]

Hello,

I do not have this advance button. All I see is a button sayin "Reset Output".

please ignore the previous post.
The user is a beta tester and the current feature has not been released. The new software is not considered stable as of yet.

Please be patient and you shall soon have it for use.

I thought I had seen it somewhere!!!

I too am a beta tester but last night was using the stable software.


Cheers!

So I've tried setting the DMX rate as low as it will go (20) but this would appear to be too fast still.

Does anyone else have this problem with their Eurolite TS5?

Tom wrote:So I've tried setting the DMX rate as low as it will go (20) but this would appear to be too fast still.

Does anyone else have this problem with their Eurolite TS5?

are you sure that it is the dmx refresh rate which is the problem?

Tom wrote:It's currently too fast for my scans to 'see' so they are not working properly.

can you describe how they not work "properly"? how do they react? are yoy sure you a using a fixture which is identical to your lights?

The pan and tilt work but the other channels do not. I am sure the fixture file is correct.

Putting a linebacker in solves the issue which is why I think it is a DMX issue

what is a linebacker?

A little device that monitors the DMX - it's made by Zero 88 - and lets you know if the DMX drops and puts up a backup state if this happens. In monitoring the DMX it slows it down just enough for the scans to work - I think that's why they work when it's in anyway.

Tom wrote:So I've tried setting the DMX rate as low as it will go (20) but this would appear to be too fast still.

Does anyone else have this problem with their Eurolite TS5?

Thats the wrong way.
20 msec is actually the fastest. It states a delay, 20msec.
So 50 msec is the slowest, wich is default and the internal refresh rate of previous FreeStyler versions.

I doubt it has something to do with the refresh rate. Maybe there's something else going on, the Enttec open USB interface has many known issues. This might be one.
Maybe your USB voltage is to low, but just high enough for the interface to work, but to low for creating a good DMX signal, causing your scanners to fail.
You can try connecting an active USB hub (with external power source!). Some people managed to fix certain problems with that.
But, since your PAN/TILT channels do work, I'm pretty sure none of the above is the case. With bad DMX signal, bad cabling or unterminated cables, really strange things can happen, but PAN/TILT working and other channels don't. <- Not possible.

You really should check and double check if your fixture file is correct. Maybe even post the fixtures manual and the fixture file here for review.
Maybe your fixture has some internal settings, causing that it only listens to PAN/TILT operations. (just guessing now).
Also do a cross check, so make a fixture file with enough channels and just try to change the sliders of each channel, checking if the fixture is responding to it.

Anyhow, what I'm trying to tell you; don't put all your money on the refresh rate thing.

Onge wrote:

Wikipedia DMX512-A wrote:...
A full packet takes approximately 23 mS to send, corresponding to a refresh rate of about 44 Hz. For higher refresh rates, fewer channels can be sent. This is accomplished by simply starting a new packet before all 512 channels have been sent. The minimum packet length is equivalent to 24 channels. Most transmitters send all 512 channels though, as many receivers have trouble with shorter packets.
...

So as Remco_k said making the refresh 20ms is actually faster and you will possibly lose DMX data.

Full DMX512-A specification can be found in our DMX Wiki or the Wikipedia DMX512-A

The refresh rate setting in FreeStyler actually has nothing to do with the time needed to send a DMX packet of 512 channels. (23 msec).
That setting in FreeStyler is just the rate at which FreeStyler sends the DMX data of all channels to the driver of the DMX interface.
Then de driver itself (or the interface in case of the Enttec PRO version) (or in some cases FreeStyler itself - Enttec Open DMX) takes care of sending the DMX packet conforming the DMX512-A standard, so when sending 512 channels the time needed for sending the complete packet is always 23 mSec, regardless of the refresh rate set in FreeStyler.
So setting the refresh rate to 20 or 50, does not actually change the DMX protocol that is sent out on the cable. It just sets FreeStyler to update new DMX values to the driver/interface) faster. Meaning that a fixture responds approx 30 mSec faster, but the DMX protocol and timing remains just the same.

The story gets different when configuring FreeStyler to sent lesser channels on the DMX output. Then the 23 mSec for the packet gets about 13 mSec for sending 256 channels.
But still does not have anything to do with the refresh rate setting in FreeStyler.

Among others this is why I think changing the refresh rate within FreeStyler is not the solution/workaround for the problems that Tom describes. Something else has to be the problem.

Onge wrote:Thanks remco_k for that information about the refresh rate within FreeStyler, I can fully understand the difference now.
Would make a difference if the interface does not have an on-board processor ?

It should not, because it won't be DMX512-A anymore, causing only more troubles. If it does, then there is a bug in the interface driver or FreeStyler.

I think that all processorless DMX interfaces have an corresponding driver (the Velleman VM116/K8062 has for sure (K8062.exe)), they take care of keeping up with the DMX 512-A protocol. FreeStyler does not have to do that, "he" just sends channel values when "he" wants to the driver.
Meaning that it might be possible that FreeStyler does not send any values for 40 seconds* or so, the DMX interface driver should not care about that and just keep on generating the DMX512-A protocol on its output using the last known values.
I think the same goes for the Enttec Open DMX interface but also for all other interfaces with processors.

* Its not that FreeStyler does stop output for some amount of time. It never does, but I just use this as an example.

Sorry I'm late but it's been very busy!

I thought I mentioned, but maybe I'm wrong, that this problem isn't just with Freestyler so it isn't a problem with the PC or interface - it happens with all real lighting desks ranging from the Avolites Pearl (lovely desk and I've got one out on hire next week) to the Zero 88 Fat Frog (Really don't like this desk!)

I think the scans don't like something in the DMX signal.

Might have to hire the linebacker and see what's causing them issues.

Strange...

the Zero 88 Fat Frog (Really don't like this desk!)

Try the zero88 Leap frog 48. One of the best desks ive used and in a price war on the pearl or tiger it wins every time!

I would pick a Tiger of Pearl over a Leapfrog anyday - if it's for an event which I can run off the subs.

The theatre stack on the Leap Frog is far superior to that of the Avo desks, which is crap, but I still love Avo desks and would pick one as a general all rounder over the Leap Frog.

Ive had my frog for about a year now and nobody could change my mind!

The cost alone won me over but the functionallity and useablity of it is exellent, plus the support from zero is second to none.

You can keep your Avo desk!!! (each to their own is suppose, Its not what you got its what you do with it!)

Out of interest which Avo desk did you use and what did you use it for?

If I'm just doing a generic rig though, ETC Express all the time!

We have a Zero 88 Sirius and yes the Z88 support really is amazing. But then so is the Avo support.

Ive used a Pearl and a Tiger (although not in huge amounts). Did use a Hog for a while but dont like to talk about that.

As for what I use / used them for ...

I run a production company that does all sorts really. Mostly corporate stuff with a band and a dj or whatever.
Ive done theatre, clubs, concerts, you name it.