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Version: 1.0.0

OPC UA WebClient

The TwinEdge OPC UA WebClient is a free browser-based tool for accessing OPC UA servers without any software installation.

Access​

Open in your browser:

https://opcua.twinedgeai.com

No download or installation required!

Features​

  • Zero installation: Runs entirely in browser
  • Cross-platform: Works on any device with a browser
  • Secure proxy: Connect via TwinEdge relay
  • Real-time monitoring: WebSocket-based subscriptions
  • Mobile friendly: Responsive design
  • Share sessions: Collaborate with team members

How It Works​

┌──────────┐     HTTPS      ┌──────────────┐    OPC UA    ┌──────────────┐
│  Browser │ ───────────>   │  TwinEdge    │ ──────────>  │  Your OPC UA │
│ WebClient│ <───────────   │  Relay       │ <──────────  │  Server      │
└──────────┘                └──────────────┘              └──────────────┘

The WebClient connects to your OPC UA server via a secure relay, enabling browser access to OPC UA servers.

Getting Started​

Connecting to a Server​

  1. Go to opcua.twinedgeai.com
  2. Click New Connection
  3. Enter server details:
    • Server URL: Your OPC UA endpoint (public IP required)
    • Security Mode: None, Sign, or SignAndEncrypt
    • Authentication: Anonymous or Username/Password
  4. Click Connect

Prerequisites​

Your OPC UA server must be:

  • Accessible from the internet (or use our tunnel feature)
  • Configured to accept the TwinEdge relay certificate
  • Firewall configured to allow port 4840 (or custom port)

Using the Tunnel Feature​

For servers behind firewalls:

  1. Download the TwinEdge Tunnel agent
  2. Run on your local network
  3. Connect via tunnel URL: tunnel://YOUR_TUNNEL_ID

User Interface​

The left sidebar shows:

  • Connections: Saved server connections
  • Recent: Recently accessed servers
  • Bookmarks: Saved node paths

Node Browser​

The main panel displays the OPC UA namespace:

  • Tree view of Objects, Types, Views
  • Search bar for finding nodes
  • Breadcrumb navigation

Details Panel​

Right panel shows selected node information:

  • Node attributes
  • Current value (for variables)
  • Child nodes summary

Subscription Bar​

Bottom bar shows active subscriptions:

  • Current values
  • Update timestamps
  • Unsubscribe buttons

Browsing Nodes​

  1. Expand Objects to see server objects
  2. Click folders to expand
  3. Click variable nodes to see values
  4. Use breadcrumbs to navigate back

Searching​

Use the search bar to find nodes:

Search: Temperature
Results:
├── Objects/Pump_001/Temperature
├── Objects/Pump_002/Temperature
└── Objects/HVAC/Temperature

Bookmarking Nodes​

Save frequently accessed nodes:

  1. Navigate to the node
  2. Click the bookmark icon (⭐)
  3. Access from Bookmarks in sidebar

Reading Values​

Single Value​

  1. Navigate to a variable node
  2. View current value in Details panel
  3. Click Refresh for latest value

Multiple Values​

  1. Select multiple nodes (checkboxes)
  2. Click Read Selected
  3. View results in table

Copy Values​

Click the copy icon to copy:

  • Node ID
  • Current value
  • Timestamp

Writing Values​

Write a Value​

  1. Navigate to a writable variable
  2. Click Write button
  3. Enter new value
  4. Confirm write operation

Data Type Handling​

The WebClient handles common data types:

  • Boolean: Toggle switch
  • Numeric: Number input with validation
  • String: Text input
  • DateTime: Date/time picker
  • Arrays: JSON editor

Subscriptions​

Creating Subscriptions​

Monitor values in real-time:

  1. Navigate to a variable
  2. Click Subscribe (👁 icon)
  3. Value appears in subscription bar
  4. Updates stream in real-time

Subscription Settings​

Configure via Settings:

  • Publishing Interval: 500-10000 ms
  • Max Items: Maximum subscribed items
  • Auto-Subscribe: Subscribe on click

Viewing Subscribed Values​

The subscription bar shows:

  • Node name
  • Current value
  • Last update time
  • Value change indicator

Click a subscription to jump to node.

Exporting Subscription Data​

  1. Click Export in subscription bar
  2. Choose time range
  3. Download CSV file

Session Management​

Saving Connections​

Save server connections for later:

  1. Connect to server
  2. Click Save Connection
  3. Enter a name
  4. Connection saved to browser storage

Sharing Sessions​

Share your session with colleagues:

  1. Click Share button
  2. Copy the session link
  3. Others can view (read-only) your session
warning

Shared sessions expire after 24 hours. Don't share sessions with sensitive data.

Session History​

View past sessions:

  • Recent connections
  • Browse history
  • Read/write log

Security​

Data Privacy​

  • No data stored on TwinEdge servers
  • Sessions encrypted end-to-end
  • Credentials never transmitted to relay

Server Certificate Handling​

If the server certificate is untrusted:

  1. Certificate details displayed
  2. Click Trust for Session
  3. Or use Security Mode: None (testing only)

Best Practices​

  1. Use SignAndEncrypt for production servers
  2. Don't save credentials in browser
  3. Use unique usernames for audit trail
  4. Review relay logs regularly

Mobile Usage​

Responsive Design​

The WebClient works on mobile:

  • Collapsible panels
  • Touch-friendly controls
  • Swipe navigation

Mobile-Specific Features​

  • Quick connect from QR codes
  • Push notifications for subscriptions (PWA)
  • Offline viewing of cached data

Limitations​

Compared to Desktop Client​

FeatureWebClientDesktop
Connection via relayRequiredDirect
Certificate managementLimitedFull
Historical dataRead-onlyFull
Method callsNot yetYes
File transferNoYes

Technical Limits​

  • Max 50 subscriptions per session
  • Max 1000 nodes per browse
  • Max 1 hour session (re-login required)
  • Relay bandwidth: 10 Mbps

Troubleshooting​

Connection Issues​

"Cannot connect to server":

  • Verify server is accessible from internet
  • Check firewall rules
  • Ensure relay certificate is trusted

"Session expired":

  • Sessions timeout after 1 hour
  • Click Reconnect
  • Save connection for quick reconnect

Slow performance:

  • Reduce subscription count
  • Increase publishing interval
  • Use desktop client for heavy usage

Browser Compatibility​

BrowserSupported
Chrome 90+Yes
Firefox 88+Yes
Safari 14+Yes
Edge 90+Yes
Mobile ChromeYes
Mobile SafariYes

API Access​

Embed in Your App​

Embed the WebClient in an iframe:

<iframe
  src="https://opcua.twinedgeai.com/embed?server=opc.tcp://server:4840"
  width="100%"
  height="600"
></iframe>

URL Parameters​

ParameterDescription
serverPre-fill server URL
themelight or dark
modebrowse, subscribe, minimal

Support​

Next Steps​