Node-RED nodes for Weidmüller u-OS Data Hub. Read, write, and provide variables via NATS protocol with OAuth2 authentication. Features: Variable Key resolution, custom icons, example flows, and provider definition caching.
npm install node-red-contrib-uos-natsUnofficial 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
---
| 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.). |
---
Run the following command in your Node-RED user directory (usually ~/.node-red):
``bash`
npm install node-red-contrib-uos-nats
Restart Node-RED. The nodes will appear in the "Weidmüller DataHub" category.
---
1. Open u-OS Web UI (Control Center → Identity & access → Clients).
2. Click Add client.
3. Name: nodered (example).hub.variables.*
4. Scopes: Select all scopes.
5. Copy Client ID and Client Secret.
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).nodered
- Client Name: Important! Give it a name (e.g. ).
- Client ID / Secret: Paste from Step 1.
4. Click Test connection.
Import this flow to test reading and writing immediately:
`json`
[{"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"}]
---
).
- 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.$3
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).$3
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.---
$3
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.$3
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.---
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.