Art-Net sample

Using the Art-Net sample bundle

The Art-Net example bundle in samples/artnet-console demonstrates the ability send data via Art-Net to e.g., open lighting architecture or professional lighting equipment. Here is a guide to how to get it working. The underlying service is using jeffreykog/node-artnet-protocol as its library.

Prerequisites

You will need a working nodecg-io installation. If you have non yet take a look at installation guide. You may need to install this bundle, so take a look at the “Try an included sample”-Guide. It will also tell you how to log in and how to use the GUI.

You also need:

A working Art-Net Node in the current network

Configure the Art-Net sample bundle

In NodeCG, create a new Art-Net service instance.
Enter the host to witch the service should broadcast:

Host

The broadcast address the Art-Net library will use to send dmx packages.
```
{
    "host": "127.0.0.1"
}
```
After entering it, click save.

Info

You may overwrite this broadcast address in code with client.bind("host address");.
Set the sample's (artnet-console) dependency to be the newly created service instance (of type artnet).
Check the NodeCG logs. You should see data logged.

Explanations

Receiving DMX data

client.onDMX((dmx) => {
    // dmx contains an ArtDmx object
    nodecg.log.info(dmx.universe, dmx.data);
});

The data you receive has the following fields:

declare class ArtDmx {
    opcode: number;
    protocolVersion: number;
    sequence: number;
    physical: number;
    universe: number;
    data: number[];
    constructor(sequence: number, physical: number, universe: number, data: number[]);
    isSequenceEnabled(): boolean;
    static decode(data: Buffer): ArtDmx;
    toString(): string;
    encode(): Buffer;
}

Sending DMX data

// send new data every 0,8 seconds.
// This is the official timing for re-transmiting data in the artnet specifciation.
setInterval(() => {
    client.send(
        universe,
        values // number[] of values for each of the 512 channels
    );
}, 800);

Note

Since neither this library nor nodecg-io currently contains an abstraction that abides the timings specified by the specification, it is important for your implementation to respect this part of the specification:

However, an input that is active but not changing, will re-transmit the last valid ArtDmx packet at approximately 4-second intervals. (Note. In order to converge the needs of Art- Net and sACN it is recommended that Art-Net devices actually use a re-transmit time of 800ms to 1000ms). — Art-Net 4 Specification p. 48