Unofficial Node-RED Package for Weidmüller u-OS Data Hub

Read, write, and provide variables via NATS protocol using OAuth2 authentication. Optimized for high performance and real-time updates.

IMPORTANT: These nodes MUST run directly on the u-OS device (e.g. as a simplified App or Snap). The system's NATS server is NOT accessible from the outside (blocked by firewall/binding). You cannot use this package from a remote Node-RED instance (e.g. on your Laptop) to connect to the device.

Maintained by IoTUeli. Source: GitHub

Nodes Overview

| Node | Purpose | |------|---------| | u-OS Config | Central configuration for NATS connection and OAuth credentials. | | Read | Subscribe to variable changes from system providers (e.g. u_os_adm). | | Write | Send commands to change variables in other providers. | | Provider | Create your own provider to publish variables to the Data Hub. | | u-OS | Unified HTTP Interface for Variables & System Admin (Reboot, Networking, etc.). |

Installation

Run the following command in your Node-RED user directory (usually ~/.node-red):

npm install node-red-contrib-uos-nats

Restart Node-RED. The nodes will appear in the "Weidmüller DataHub" category.

Quick Start

1. Create OAuth Client (in u-OS)

1. Open u-OS Web UI (Control Center → Identity & access → Clients).
2. Click Add client.
3. Name: nodered (example).
4. Scopes: Select all hub.variables.* scopes.
5. Copy Client ID and Client Secret.

2. Configure Node-RED

1. Drag a Read node to the canvas.
2. Click the pencil ✏️ next to Connection.
3. Enter:
   • Host: IP of your u-OS device (e.g. 127.0.0.1 for local).
   • Client Name: Important! Give it a name (e.g. nodered).
   • Client ID / Secret: Paste from Step 1.
4. Click Test connection.

3. Example Flow

Import this flow to test reading and writing immediately:

[{"id":"cdad2fa96dc6eeec","type":"datahub-input","z":"c221537c994b056a","name":"Read Zipcode","connection":"a0ba0e15c8dad779","providerId":"u_os_adm","manualVariables":"digital_nameplate.address_information.zipcode:2","triggerMode":"event","pollingInterval":"1000","x":190,"y":100,"wires":[["315d179d66bf9b93"]]},{"id":"315d179d66bf9b93","type":"debug","z":"c221537c994b056a","name":"Debug Output","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":440,"y":100,"wires":[]},{"id":"a0ba0e15c8dad779","type":"uos-config","clientName":"nodered-client"}]

Node Usage

Read (DataHub Input)

Reads values from existing providers (like u_os_adm).

• Provider ID: Name of the source provider.
• Variables: Use Load Variables to browse and select variables.
  • New: Supports Multi-Select and Categorization (Grouped by prefix).
• Trigger: "Event" (instant update) or "Poll" (interval).
• Chunking (New): Automatically splits large requests (>100 variables) to prevent timeouts.

Write (DataHub Write)

Changes values in other providers.

• Single Mode: Select a variable from the list. Send msg.payload = value.
• Batch Mode: Select NO variable (clear selection). Send msg.payload as a FLAT JSON object: {"var_key": value}.
• Strict Mode: Automatically handles Fingerprints for strict providers (e.g. u_os_sbm).

Provider (DataHub Output)

Publishes your own data to the Data Hub.

• Provider ID: Name of your provider (e.g. my-app).
• Auto-Discovery: Automatically creates variable definitions based on your input JSON structure.
• Bi-Directional: Enable "Allow external writes" to receive commands from other apps.

u-OS (API Node)

The u-OS node provides a unified HTTP interface for both DataHub Variables and System Administration.

• Mode: DataHub Variables

  • Alternative access to variables via HTTP (REST) instead of NATS.
  • Actions: Read, Write, List Providers, List Variables.
  • Useful for one-off requests or environments where NATS is restricted.
  • New: Variable Multi-Select and Grouping now supported.

• Mode: System Administration

  • Manage the u-OS device itself.
  • Categories: System (Reboot), Network, Security, Logging.
  • Requirements: You must enable System Admin Access in the u-OS Config node.

Configuration

1. Host: IP address of the u-OS device (default: 127.0.0.1 for local Node-RED).
2. Auth: Client ID and Client Secret (from u-OS Device Administration).
3. Scopes:
   • Standard scopes for DataHub are active by default.
   • Check "Enable System Admin Access" to manage the system.

Performance & Optimization

• HTTPS Agent: Secure connection handling (no global TLS override).
• Chunking: Large variable lists are split into 100-item chunks for reliable reading.
• Filter-on-Decode: High-speed filtering at the byte-level to save CPU.

⏱️ Benchmarking

You can verify the speed of your u-OS / NATS setup using the included benchmark flow.

1. Import examples/benchmark-flow.json.
2. Configure your credentials.
3. Click the inject button.
4. Check the Debug output for "Latency Result".

Expected Round-Trip-Time (RTT):

• < 4ms: Excellent (Localhost / standard)
• < 10ms: OK (High Load)
• > 20ms: System overloaded or Slow Consumer bottleneck.

Troubleshooting

• Provider not visible? Check Client ID and Scopes.
• Status "cooldown"? The node is pausing after an error to protect the network.
• Status "illegal ID"? You used a reserved name. Use nodered or similar.
• Write not working? Ensure your OAuth client has hub.variables.readwrite scope.
• Debug: Check the Node-RED "Debug" sidebar for error messages.

License: MIT

DISCLAIMER:
This is NOT an official product of Weidmüller Interface GmbH & Co. KG.
This package is maintained by IoTUeli as a community contribution.
Use at your own risk. No liability or warranty is assumed.