Q Light Controller+

Hello folks

I am doing my first DMX lighting project. Looking for some help with a flash led strip when it should be a solid color.

As a starting point I have : 1 three channel fixture define. I have a no-name USB to DMX dongle connected to a Windows 10 PC. My DMX slave is DR-DMXTCON-3CH-LV driving a tri-colour led strip. I also included 120ohm termination resistor.

As a test, I defined a few scenes with recognizable data, mainly FF FF FF, FF 00 FF, and finally FF FF 00. As shown in the attached scope plots.


A few questions:
1) With only one fixture define, I thought the serial data stream would only include 4 slot before repeating.
2) The first four slots look correct, However the data repeats itself again approximately 29ms later. which is a bit too long for 513 slots x 44 us = 22.6ms Is this okay?
3) The second set of data does not have a break and mark after break. Why does it repeat before the break & MAB?

Any help would be appreciated. I hope I am missing something simple.
Rob

Since it's your processor which is responsible for the timing (no name usb to dmx) there are reporter cases where the refresh timing had to be lowered.
QLC+ has a parameter for that.

As is typical, the solution was very simple. Set the frequency of the USB dongle to 30hz. What slowed me down was the refresh window was perfectly sized to hide the pull down menu for the frequency. I include a scope plot below.

One more question, how do i change the maximum number of DMX channels. I tried editing the configuration file using windows regedit, but it had no effect.

first of : I like the way you debug ... looking at signal-level as a starter ... !!ToP!!

Now I'm guessing ...
Is QLC+ only sending up to the max-address used and then induces a mean-time/break-signal (not sure about wording now)

that would mean that there is a substantial difference in timing if you'd use only the first x-number of DMX channels...
versus
put your Hazer on channel 511 (what is quite common in theaters) - to get this working QLC+ has to obtain the whole timing telegram upto channel 511 and than a mean-time/break?
If so I guess that the 30Hz 'tackt-frequence' may be too high??
Not sure - therefore my compliment about your debugging skills... if you would be so kind to check.

(Next thing is doing the same @max RS485 cable length - just kidding - I did this already)
(2nd next thing : put a 16kW dimmer pack somewhere in between with all channels @145, power cables running over 10m parallel to DMX ... Can you image the electrical signal being a DMX (RS485) train? Plain and utter ugly signal ...)