Connecting Devices

In WATCHOUT, the physical outputs that render your show — displays, audio devices, and capture sources — are not tied to specific IP addresses or fixed hardware paths. Instead, each device is bound to a host alias: the human-readable name of the node where the device is physically connected. This name-based approach means your show configuration survives IP address changes, network reconfigurations, and even hardware swaps, as long as the replacement machine uses the same alias.

This article covers how devices are connected to nodes, how to assign and manage those connections, and best practices for keeping your device mapping reliable across rehearsals and performances.

How Device-to-Node Binding Works

Every display, audio device, and capture source in your show has a Host property that specifies which node should drive it. When you set a display's Host to "Stage-Left-1", you are telling WATCHOUT: "Render this display on whichever machine currently identifies itself as Stage-Left-1 on the network."

When the Director starts a show, it looks at each device's Host assignment and instructs the corresponding Runner to take ownership of that device. The Runner then initializes the physical output (GPU output, audio interface, NDI stream, etc.) based on the device's configuration.

If the host machine is not available on the network, the device remains unconnected and Producer shows a warning. When the machine comes online and is discovered, the Director automatically assigns the device to it.

Assigning a Host to a Display

To connect a display to a specific node:

1. Open the Devices window (Window > Devices) or select the display in the Stage view.
2. Open the display's properties in the Properties panel.
3. In the Host field, select the target node from the dropdown. The dropdown lists all currently discovered nodes.
4. Configure the output type (GPU, SDI, NDI, or Virtual) and output-specific settings (resolution, refresh rate, color depth, etc.).
5. The Director will assign this display to the selected node's Runner at the next show update.

Assigning a Host to an Audio Device

Audio devices follow the same pattern:

1. Select the audio device in the Devices window.
2. In the Properties panel, set the Host to the target node.
3. Choose the Device Type — WASAPI, WASAPI Exclusive, Dante, or ASIO — and configure the specific audio interface, channel count, sample format, and latency.
4. The Runner on the target node will initialize the audio output when the show starts.

For Dante audio, the Host determines which machine's Dante network interface is used. See Dante Audio for details.

Audio Channel Mapping Matrix

Each audio device has a channel mapping matrix in its properties that controls how WATCHOUT's internal audio bus channels are routed to the physical audio output channels on the hardware. This matrix is the bridge between your timeline audio and the actual speaker outputs.

Device-Level Channel Mapping

When you select an audio device in the Devices window and open its properties, the channel mapping matrix is displayed as a grid:

• Rows represent WATCHOUT audio bus channels (the internal mix buses).
• Columns represent physical output channels on the audio device.
• A purple checkmark at an intersection indicates that the bus channel is mapped to that physical output.
• To edit a cross-point, click the three dots icon at the channel intersection. A small editor opens — press Enter to confirm and close it.

The matrix includes a default variable called masterVolume, which acts as a global volume control applied to all audio output from this device. You can control this variable at runtime via Tween Expressions, input protocols (ArtNet, OSC), or the Control Window.

Each audio device also shows a heart symbol in its properties that enables or disables the device. Audio devices are disabled by default — you must enable them before they produce output. When a device is enabled and assigned to a node, the Audio Renderer starts automatically on that node.

Cue-Level Channel Mapping

Each audio cue also has its own channel mapping matrix, accessible from the cue's properties. This matrix controls how the cue's audio channels are routed into the audio bus:

• The grid layout and editing pattern are the same as the device-level matrix — purple checkmarks show mapped channels, and cross-points are edited the same way.
• The cue-level matrix includes a default variable called cueVolume, which provides per-cue volume control independent of the device-level masterVolume.

The effective output level of a cue's audio is determined by the combination of:

1. The Volume tween on the cue (see Audio Volume)
2. The cueVolume variable from the cue's channel mapping
3. The masterVolume variable on the audio device

All three factors are applied together, so a cue with a Volume tween at 50%, a cueVolume at 80%, and a masterVolume at 100% results in 40% effective output level.

Assigning Capture Sources

Capture sources (NDI streams and hardware capture devices) also use host aliases:

• NDI sources are network-based and discovered by stream name rather than by host. You add an NDI source by selecting its stream name from the list of discovered NDI streams. However, the capture is still processed by a Runner on a specific node, so the Host assignment determines which machine handles the NDI receive and decoding work.
• Hardware capture sources (webcams, capture cards, and other local devices) are bound to the node where the capture hardware is physically installed. Set the Host to that machine's alias.

See NDI Video Sources for details on NDI capture configuration.

The Devices Window

The Devices window (Window > Devices) provides a consolidated view of all output devices across your show, grouped by their host node. It shows:

• All displays, audio devices, and capture sources, organized under their assigned hosts
• Device status indicators showing whether each device is active and healthy
• Filter buttons to show All, Display, Virtual, Capture, or Audio device types

This window is the quickest way to see which devices are connected to which nodes and to spot any devices that are missing their host connection. For a full description of the Devices window interface, see The Devices Window.

Best Practices for Host Aliases

The reliability of your device connections depends on consistent, well-managed host aliases:

• Use descriptive, unique names. Aliases like "FOH-Left", "LED-Upstage", or "Audio-Main" immediately tell you what each machine does. Avoid generic names like "PC1" or "Node-A" that become confusing in larger systems.
• Keep aliases stable. Once you assign displays to a host alias during programming, do not rename the node before a show unless you also update all device assignments. Renaming a node changes its alias, which breaks the connection to any devices that reference the old name.
• Document your alias-to-hardware mapping. Especially for touring shows or multi-venue installations, keep a record of which physical machine corresponds to which alias. This makes troubleshooting and hardware replacement much faster.
• Use the same alias on replacement hardware. If a display server fails and you swap in a replacement, configure the replacement with the same host alias as the original machine. All device assignments will transfer automatically without any changes to the show file.

Failover with Duplicate Aliases

As described in Network Overview, two machines can share the same host alias as a failover strategy. If the primary machine goes offline, the backup machine (with the same alias) takes over automatically. The Director will reassign all devices that reference that alias to the backup Runner.

This provides a basic hot-standby capability without modifying the show file. However, both machines must have identical hardware configurations (same GPU outputs, same audio interfaces) for the switchover to be seamless.

Troubleshooting Device Connections

Relationship to Other Articles

• Network Overview — how services communicate and discover each other
• Display Servers — setting up the machines that host your display outputs
• The Devices Window — the Producer interface for managing device assignments
• NDI Video Sources — connecting NDI streams as capture sources or display outputs
• Dante Audio — connecting Dante network audio devices