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 does not yet contain an abstraction, so the data is sent to the timings set by the specification, you should respect this part of specification in your implementation.

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