@dusx
If I made what you propose, the lamp flash randomly. But I don't understand why or what happen with this change. I don't have the same fixture and for my test I don't use this patch. I have a Botex Dimmer with 4 sockets. In one sockte I have a normal office lamp)it could be also a motor) and I use the simple patch I sent you- With this patch I get also randomly flash of the lamp and a randomly flashing of the 4 channel on the dimmer but so what…
I think I will buy another USB DMX. I read here (unfortunately only in german) https://wiki-de.dmxcontrol-pro... that there is two sorts of usb Dongle: activ and passiv. Activ are better and use the DMX USB Pro protocol but I have a passive using the open DMX USB protocol. A problem is that information (active or passiv) seems to be a secret and cannot be find in the product descritions.
Thank you for your help but I think I let it with my workaround or a new dongle. To bad, I found it was a good solution for students because the interface was very cheap and convenient for small project or test.
best
Jean-François