I must say, that until now I never had problems using QLC+ with my ENTTEC device. But yesterday it was really annoying...
I have to prepare my stuff for a show on the upcoming weekend. The venue has lighting in the DMX address space beginning at 400 and up. So I tried to simulate this yesterday with my private hardware. I knew hard- and software being really reliable, but now I have the following problem:
1. I configure my device with address 400
2. I config the software to use this device
3. I test it using the simple desk
4. nothing happens for minutes
5. I go to "play" mode and I end it. Nothing happens.
6. I go to "play" and do something that ends in a dialog (quit the software etc,): I answer the dialog and the device does its job immediately...
7. I configure my device with address 1
8. All works immediately
Is this a known problem or is there a bug that you did not see yet? Might there be a problem working with addresses above 256 (I guess)?
Can you help me till upcoming saturday, or do I have to work with the hardware at the venue?
Problem with ENTTEC OPENDMX USB and higher DMX addresses
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GGGss
- Posts: 2786
- Joined: Mon Sep 12, 2016 7:15 pm
- Location: Belgium
- Real Name: Fredje Gallon
You are facing a timing issue problem.
DMX sends a train of packets down the line. It starts with a burst signal (the locomotive if you like) - every fixture starts counting the wagons passing by. If the xth wagon passes by (xth being the address of the fixture) the logic of the fixture looks inside the wagon to find a value.
Now ... if timing is off or disturbed, it may be that the fixture miscounts the amount of wagons passing by ...
What can be wrong here:
* The train is truncated by software (not all 512 wagons are sent)
* Cables have a wrong impedance (as per standard they have to be 120 Ohm) which introduces reflections which may disturb timing.
* there are too many devices on one bus (and the driver can deliver enough power for the receivers)
* the line length is off spec.
* the line isn't terminated
* the sender isn't capable to hold its pace (overrun / underrun) -> and since with your device it's the processor inside your computer which is responsible for the timing; issues can occur.
I'd suggest to start lowering the tact frequency of the DMX interface. There are quit some posts tackling this issue.
DMX sends a train of packets down the line. It starts with a burst signal (the locomotive if you like) - every fixture starts counting the wagons passing by. If the xth wagon passes by (xth being the address of the fixture) the logic of the fixture looks inside the wagon to find a value.
Now ... if timing is off or disturbed, it may be that the fixture miscounts the amount of wagons passing by ...
What can be wrong here:
* The train is truncated by software (not all 512 wagons are sent)
* Cables have a wrong impedance (as per standard they have to be 120 Ohm) which introduces reflections which may disturb timing.
* there are too many devices on one bus (and the driver can deliver enough power for the receivers)
* the line length is off spec.
* the line isn't terminated
* the sender isn't capable to hold its pace (overrun / underrun) -> and since with your device it's the processor inside your computer which is responsible for the timing; issues can occur.
I'd suggest to start lowering the tact frequency of the DMX interface. There are quit some posts tackling this issue.
All electric machines work on smoke... when the smoke escapes... they don't work anymore
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FastEddy
- Posts: 3
- Joined: Mon Mar 11, 2019 7:08 pm
- Real Name: Stefan Jurisch
Thanks for that quick answer!
I first thought it might be the impedance because I forgot the terminator. But it is not. So I guess I really have to lower the frequency. But I have absolutely no idea how to do that. And I cannot find any issue that describes that.
Best regards, Stefan
I first thought it might be the impedance because I forgot the terminator. But it is not. So I guess I really have to lower the frequency. But I have absolutely no idea how to do that. And I cannot find any issue that describes that.
Best regards, Stefan
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edogawa
- Posts: 586
- Joined: Thu May 07, 2015 10:34 am
- Real Name: Edgar Aichinger
On Input/Output tab, right side panel, select the DMXUSB line representing your interface, and click the toolbox button in the lower half of the screen. the dialog appearing should let you change the frequency.
This has been added in 4.12.0 so you won't find it in an older version.
This has been added in 4.12.0 so you won't find it in an older version.
