FS always outputs 512 channels?

[remco_k]

Today I put my own Velleman K8062 USB DMX interface together. Boy, that was old school solder work. Was a long time ago for me. But; the interface works (I gues, don't have a fixture here to test it), but the DMX led is blinking. So that seems ok.

I wonder if I have the following statement correct:

Does FS always set the output interface to 512 channels regardless of the maximum DMX channel needed?

According to the DMX512 protocol, FS (or any light controller software) can optionally only be outputtig 10 DMX channels and then start over at channel 1. Resulting in theoreticly faster responsive fixtures.

I can't test this (no DMX fixtures here). But I just have a little clue that FS always sets the DMX output interface to 512 channels.
Here comes the clue:
My interface has a nice little red led on it "DMX signal". It flashes on and off around every 500 msec when I start freestyler.
But, when I start the test tool that is delivered with the interface, I can set the max number of output channels to 16..512 with steps in between. If I set the num output channels to 256 the led blinks way faster, exactly 2 times: every 250msec it goes on and off. So I assume that the led indicaties how fast all the DMX outputs are transmitted. Maybe divided by some number to decrease the number of flashes or so.
If I set the number of output channels to 512 then the led flashes at the same rate as it does when I start FreeStyler.

You might wonder why I ask this; I know DMX transfer is really fast (250kbaud or so?).
First of all, I don't have any DMX fixture to test, soon I'll be having one a few days for testing. But I have this question now and I just wonder...
If FS is indeed always set the output interface to 512 channels, would it be better to set the max DMX channel by user settings (e.g. max DMX channel 10)? Would the DMX transfer have a much faster loop? (That should be a Yes as answer)
But: Would the fixtures respond noticeable faster to the controlls of FS?
This last question is what I don't know. Considering the high baudrate, I think any general light jock like you and me doest notice the faster responsive fixtures at all. They respond faster when we measure it, that I am sure of. But is it noticeable?

[aquas]

I, about this i think that the "machine" PC that you use influence the timming. I've tried to use my desktop and my laptop on live, with freestyler(obevious), and it's simple... The USB converter is the cheapest and most popular, the Enttec open dmx. So the open dmx has a "problem", don't have "clock"(sorry i say that), the PC is the clock...it means that PC fast ---> Clock fast, more fast response on fixtures. My laptop is a old Compaq Presario 2100, only with 192Mb of ram... and the desktop a old Athlon 1500+ with 512Mb. It's totaly diferent the response of the fixtures on the two PC, more faster PC more faster fixtures.
I write this to explain if your serial converter don't generate "clock", using freestyler could be slower on PC that using the tester.

Cumpr

[remco_k]

I, about this i think that the "machine" PC that you use influence the timming. I've tried to use my desktop and my laptop on live, with freestyler(obevious), and it's simple... The USB converter is the cheapest and most popular, the Enttec open dmx. So the open dmx has a "problem", don't have "clock"(sorry i say that), the PC is the clock...it means that PC fast ---> Clock fast, more fast response on fixtures. My laptop is a old Compaq Presario 2100, only with 192Mb of ram... and the desktop a old Athlon 1500+ with 512Mb. It's totaly diferent the response of the fixtures on the two PC, more faster PC more faster fixtures.
I write this to explain if your serial converter don't generate "clock", using freestyler could be slower on PC that using the tester.

Cumpr

The 'problem' I am describing has nothing to do with the computer I am using because another program on the same PC let the DMX led blink way faster when I set it to less DMX channels like 256. It blinks the same rate as freestyler when set to 512 DMX channels.
If it had anything to do with the computer I am using, then I would not have a faster blinking led, would it?
Here my qoute what describes this:

But, when I start the test tool that is delivered with the interface, I can set the max number of output channels to 16..512 with steps in between. If I set the num output channels to 256 the led blinks way faster, exactly 2 times: every 250msec it goes on and off. So I assume that the led indicaties how fast all the DMX outputs are transmitted. Maybe divided by some number to decrease the number of flashes or so.
If I set the number of output channels to 512 then the led flashes at the same rate as it does when I start FreeStyler.

Also, the CPU load of my computer stays at the bottom of 0 to 10%, so that is not quite the issue here.

Its not that I have problems with the speed, I just wonder that it may be a noticeable change in 'fixture reaction speed' if FS would be only putting out the max number of channels that a user needs. Like 10. (or 100)...
Now it seems to always put out 512 channels. Regardless of the real max number of channels you need.

So the point I am 'worried' about is only on the DMX512 line. It has nothing to do with slow computers or USB interfaces with or without 'clock'.*

offtopic:
* The Velleman K8062/VM116 certainly has an internal clock (and Microcontroller) - it can run standalone (although really basic), without 'clock' and microcontroller that would be impossible. Or did you mean that the Enttec open dmx has no 'clock'?

Edit: I looked it up; the Enttec Open DMX does not have a 'clock' or microcontroller on board so I guess you meant that, it uses a default USB to Serial device: FTDI232BM. In this case the computer needs to do 'all of the work' constantly and is therefore much more dependant on the CPU of the computer than a 'microcontroller enabled interface' like the Velleman. And then again; when FS is adapted to only output the max number of channels a user needs, then the performance could be better. Would that be noticeable by the operator? It might be.

[aquas]

Ok, i'm sorry i think that i don't understand very well your post... forget it!!!! but i was thinking that you use an Hardware to teste, not the computer...
For your question, i think that only Ralph can answear!!!

thanks

[remco_k]

And some weeks later, I had another problem:
'Slow' response on flash button

Turns out that FS does always put out 512 channels on the Velleman VM116 interface and that it does have an effect on fixture response times.
So, now I have an beta version of FS, where I can set the max number of output channels. That speeds up things a lot!
(together with an improvement on the internal refresh rate in FS its hell of a lot faster...)

[kikabyte]

Can we use the total channel control with other interface units or just the velleman??

[remco_k]

Can we use the total channel control with other interface units or just the velleman??

In FS this feature was already implemented for some interfaces. Now Raph added the implementation for the Velleman VM116.
If your interface supports this (what it should do, because this is normal functionality) than you could ask Raph to implement this feature for your interface type. If your interface does'nt have this functionality, then there's nothing to do about it. Except for buying another interface who does.

Wich interface are you using?

[kikabyte]

I have a vellaman for test projects, and an afterglow installed in our band computer rack (which i think still only runs properly if you select the 'Entec Open DMX' interface ins freestyler!).

Can't wait for the next release, would love to use it on Saturday night!

[Röschi]

I'm using the uDMX interface, which is also able to output only the channels that have been changed. It would be great if Raph could add this nice feature also to the uDMX!

I think a global setup for this feature could be possible as well?! You just have to know if the used interface is able to do that, else this option would be ignored?

[remco_k]

I'm using the uDMX interface, which is also able to output only the channels that have been changed. It would be great if Raph could add this nice feature also to the uDMX!

I'm not sure if Raph is reading along here, maybe you can ask here: Ideas and Remarks

I think a global setup for this feature could be possible as well?! You just have to know if the used interface is able to do that, else this option would be ignored?

It is (and was, I did not know that either) already a global setting on the interface selection screen, but it gets hidden when you've selected an interface where Raph did not implement the max channels code.
And there is the problem, every interface has its own driver, speaks its own language. This type of feature is very driver and interface specific, there is no way to implement this feature only once and then have it for all interfaces. It needs internal implementation for each interface seperately. Then the global setting can be used for controlling the max num channels.

[Jarvis]

Not sure if this is the right place to request it, but is it possible to have a copy of the beta made available where you can assign max channels for the Velleman module? I too am having the same slow response problems. Sorry new here (and to FS) and still finding my way round the forum threads. From what I can see FS looks a great piece of software if only my lights would respond more frequently so I could put it through it's paces

[Eagle]

Hello,

Same thing for me, I'm using Freestyler for one year on moving heads and RGB LED displays. I would actually like to be able to send only the channels I'm using to get a better refresh rate. It could be helpful on LED for strobing as an example. I am using Vellaman VM116. I'm willing to test that beta version. However, I'm not using the special features you requested testers to test.

Thank you,

Eagle