Setting up the Relackout USB-DMX interface

If your USB-DMX interface isn’t an ENTTEC Open DMX USB plugged straight into the computer running Relackout — or you want that interface to sit on a completely different machine — Relackout’s built-in USB DMX output can’t help, but a free, standalone companion app can. This guide covers Relackout ArtNet 2 USB: what it is, how to install it, how to connect a USB-DMX interface to it, and how to route Art-Net from Relackout into it over your network. It’s a separate program from Relackout itself, with its own window.

What is this tool?

Relackout ArtNet 2 USB — listed in relackout.com’s navigation as Artnet to USB — is a free, open-source companion app from the Relackout team. It has nothing to do with your Relackout license: it runs entirely on its own, with no account and no login, and works with any Art-Net source on your network, not only Relackout. It ships in two forms that share one configuration file:

• A desktop app with a window: auto-discovery of Art-Net broadcasts, a live 512-channel preview, and a visual routing table.
• A headless command-line tool, artnet2usb-cli — the exact same routing engine with no window at all, built for a machine with no screen attached.

Both read and write the same config file, so you can build a route in one and run it in the other.

A few things worth knowing before you install it:

• It finds every Art-Net universe on your network automatically, including nodes that aren’t broadcasting DMX yet.
• It can show a live preview of all 512 channels of any discovered universe before you route it anywhere.
• It speaks two USB DMX protocols: Enttec DMX USB Pro, and raw Open DMX / FTDI.
• It remembers a USB interface by its hardware identity (vendor, product, serial number) rather than which port it’s plugged into — rename it once, and the name and its routes survive being unplugged and moved to a different port.
• You choose what happens if the Art-Net signal drops: hold the last frame, or blackout the output.
• The desktop app’s interface is available in English, Deutsch, Français, Italiano and Türkçe.

A quick look at the app

1. 1

   Open Relackout ArtNet 2 USB. Its window splits into an Art-Net Broadcasts panel and a USB Devices panel side by side, a pairing bar below the devices, and a Routes panel — all empty until something broadcasts or gets plugged in.

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2. 2

   The Art-Net Broadcasts panel lists every Art-Net universe it sees on the network. With nothing sending yet, it says so plainly.

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3. 3

   The USB Devices panel lists every connected serial device it can see. With no USB-DMX interface connected yet, it says so plainly.

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4. 4

   Below the device list sits the pairing bar — pick a broadcast and a device, a protocol and a refresh rate, then click Create route & start — and below that, the Routes panel, empty until the first route exists.

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How this differs from Relackout’s built-in USB DMX output

Relackout already has a USB DMX output of its own, covered in DMX output: Art-Net, sACN and USB DMX — but it only speaks to an ENTTEC Open DMX USB interface (or a firmware-compatible clone), and only when that interface is plugged straight into the same computer that’s running Relackout.

Relackout ArtNet 2 USB adds exactly the two things the built-in output can’t do:

• A second protocol. It also speaks Enttec DMX USB Pro — a different USB DMX interface family that Relackout’s built-in output doesn’t recognize.
• A separate machine. The USB-DMX interface no longer has to be plugged into the computer running Relackout. Relackout already sends Art-Net out over your network (see Connection settings); Relackout ArtNet 2 USB can run on any other computer on that same network — a laptop backstage, a small server with no monitor, or a Raspberry Pi tucked behind a truss — and pick up that exact broadcast.

In short: reach for it whenever your interface isn’t an Open DMX USB plugged into Relackout’s own machine.

Installing it

Download a ready-to-run build for your platform from relackout.com, or from the project’s GitHub releases page. There’s nothing to install:

• Windows — a portable .exe; just run it.
• macOS (Apple Silicon or Intel) — a .dmg; drag and drop.
• Linux — an .AppImage; chmod +x it and run.

Connecting a USB-DMX interface

Plug your Enttec DMX USB Pro or Open DMX / FTDI interface into the computer that will run Relackout ArtNet 2 USB — remember, that doesn’t have to be the computer running Relackout — and open the app. Your interface shows up in the same USB Devices panel you saw above, in place of the “No USB serial device found” message.

Each device is remembered by its hardware identity rather than by which port it’s plugged into, so click Rename once and the name sticks even if you move the cable to a different USB port later.

Routing Art-Net from Relackout to it

Before anything else, make sure Relackout itself is sending Art-Net. Open Settings in Relackout and look at the DMX Outputs section: the Art-Net card should read Connected, with the universe you want to send checked under Broadcast universes. DMX output: Art-Net, sACN and USB DMX walks through that exact screen, including the address and port Relackout is sending to.

With Relackout broadcasting and your USB interface connected, open Relackout ArtNet 2 USB. Its Art-Net Broadcasts panel lists Relackout’s universe automatically — on the same network, there’s no IP address to type in by hand. Click the broadcast, click your USB device, pick a protocol and a refresh rate in the pairing bar shown above, then click Create route & start.

The route then appears in the Routes panel as a line you can Freeze (hold the current frame steady while you make changes upstream), Stop, or delete. Output from Relackout now reaches your interface over the network instead of a direct cable.

Headless setups: the CLI

For a machine with no screen — a Raspberry Pi behind a truss, a backstage server — the same routing engine ships without a window, as artnet2usb-cli. On a machine with exactly one Art-Net universe and one USB DMX interface connected, one command finds both and starts bridging, no prompts needed:

artnet2usb-cli auto

Run artnet2usb-cli install-service afterwards and it prints one more command; run that command once and the bridge restarts itself after every reboot or crash. The CLI reads and writes the exact same configuration file as the desktop app — build a route visually on your laptop, then run it headless on the Pi, or the other way around. The full command reference lives on relackout.com.

Troubleshooting

• Nothing shows up in Art-Net Broadcasts: Relackout ArtNet 2 USB and Relackout need to be on the same network, and nothing on it can be blocking UDP 6454.
• Nothing shows up in USB Devices: check the cable and the port; a device that was connected before but is now unplugged stays listed, tagged (not connected).
• The wrong universe, or none at all: double-check Broadcast universes in Relackout’s DMX Outputs — only checked universes go out over Art-Net.
• For a wider checklist, see Device or output not showing up; for IP addresses, the universe base, and ArtPollReply names, see Connection settings.

What’s next

Now you know when to reach for Relackout ArtNet 2 USB instead of Relackout’s built-in output, how to install it, connect an interface, and route Art-Net to it — with a window or headless via the CLI. For Relackout’s own output settings in full, see DMX output: Art-Net, sACN and USB DMX; for network and universe details, see Connection settings.