Connecting a USB-DMX adapter

For the light to leave the program and reach real fixtures, you need a USB-DMX adapter (a “dongle”): it turns the program’s commands into a DMX line signal. Connecting it takes a couple of clicks.

📍 Where: the DMX button in the program header (on the right). It’s gray when nothing is connected; once connected, a status indicator lights up.

How to connect:

Plug the adapter into a USB port on your computer.
Click the DMX button in the header — the Found devices panel opens.
Pick your adapter from the list and click Connect.
Done: the status in the header lights up, and in Live the DMX indicator turns green and shows the frame rate.

⚠️ Important: any other lighting software must be closed. An adapter is handed over to one program in full: while a neighbouring app keeps it “busy”, SvetoMaster cannot open it — the device either will not show up in the list or will not accept a single frame.

💡 Tip: if your adapter isn’t in the list (“No USB devices found”), it’s almost always a driver issue. Instructions for installing drivers for the popular chips (uDMX/libusbK, FTDI, CH340) and an automatic installer are on our website: udmx.net/driver. After installing the driver, just reopen the DMX panel.

The adapter is in the list, but it will not connect. This happens when Windows sees the adapter but denies access to it: another lighting program is holding it (sometimes it merely sits as an icon near the clock), or an old driver from the bundled disc is installed. The program names the cause itself — as a red line in the DMX panel, even if you pressed nothing and it was connecting automatically. What to do: close the other lighting programs and restart the computer; plug the adapter straight into a USB port on the computer, with no hub and no extension cable. As soon as the link appears, the message goes away by itself.

Auto-reconnect. If the adapter is unplugged on the fly or it “drops out”, the program doesn’t stay silent: the header shows the Reconnecting… status, and the link is restored on its own. The status turns green not when the device becomes visible to the system again, but only once the adapter has actually accepted the first frame: the port can open while commands still fail to get through. Until a frame goes through, the honest Reconnecting… stays on and the attempts continue.

“Restoring…” is not a disconnect. Sometimes the adapter stays in the port but stops accepting frames for a few seconds. The cause is usually not the program but the USB port, the laptop’s power supply or the hub. At that moment the header status turns amber “Restoring…”, and SvetoMaster quietly heals the link: it reopens the device and then keeps retrying at a calm pace instead of hammering an adapter that has gone silent. Output resumes on its own as soon as the adapter answers; all that time the fixtures hold their last state and do not go dark. If the outage drags on, the program honestly switches to “Reconnecting…”.

💡 Tip: if “Restoring…” shows up regularly, it is almost always USB. Try another port, a powered USB 2.0 hub (a frequently effective measure for uDMX adapters), turn off “USB selective suspend” in Windows and switch the power plan to “High performance”.

💡 If that didn’t help, check the DMX side: inexpensive uDMX adapters have no galvanic isolation, so interference from the fixtures’ power supplies travels along the cable’s ground straight into the adapter. Quick check: unplug the DMX cable from the adapter completely and leave the program running for half an hour. If the outages are gone, you need a galvanic DMX isolator (or an isolated splitter) between the adapter and the fixtures, a 120 Ω terminator on the last fixture and a properly earthed socket. On a laptop the “run on battery” check has the same meaning: if there are no failures on battery power, the interference comes in through the mains.

If your USB-DMX adapter (controller) isn’t supported by SvetoMaster yet, write to support — udmx.net/soft/support — and we’ll try to add it (where technically possible). You might also consider buying one of the popular adapters (controllers) — SvetoMaster supports even inexpensive modern “dongles”.

💡 Tip: a handy way to check that the signal is actually getting through is the Console: raise a fixture channel fader — the fixture should respond. If it doesn’t, check the DMX address and the line’s terminator/cable.