OPC UA Sync Tool

A tool to export nodes/values from an OPC UA server to a file, and import them into another OPC UA server.

Features

• Stage 1 (Export): Browse and read all nodes/values from a source OPC UA server and save to a JSON file
• Stage 2 (Import): Read nodes/values from a JSON file and write them to a destination OPC UA server

Installation

Option 1: Use Pre-built Executables

Download the latest executables from the GitHub Actions artifacts (built automatically on push to master):

• export_opc_nodes.exe - Export tool
• import_opc_nodes.exe - Import tool
• create_nodes_from_export.exe - Create server from export

Place the executables in the same directory as the PowerShell scripts.

Option 2: Install Python Dependencies

pip install -r requirements.txt

Building Executables Locally

To build executables yourself:

pip install pyinstaller
pyinstaller export_opc_nodes.spec
pyinstaller import_opc_nodes.spec
pyinstaller create_nodes_from_export.spec

The executables will be in the dist/ directory.

Usage

Stage 1: Export from Source Server

python export_opc_nodes.py --source-url opc.tcp://localhost:4840 --output-file nodes_export.json

Options:

• --source-url: OPC UA server endpoint URL (default: opc.tcp://localhost:4840)
• --output-file: Output JSON file path (default: opc_nodes_export.json)
• --username: Optional username for authentication
• --password: Optional password for authentication
• --security-policy: Security policy (default: None, options: Basic128Rsa15, Basic256, Basic256Sha256)
• --security-mode: Security mode (default: None, options: Sign, SignAndEncrypt)

Stage 2: Import to Destination Server

There are two ways to import:

Option A: Write values to existing nodes

python import_opc_nodes.py --destination-url opc.tcp://localhost:4841 --input-file nodes_export.json

This assumes the destination server already has the same node structure. It only writes values to existing nodes.

Options:

• --destination-url: Destination OPC UA server endpoint URL (default: opc.tcp://localhost:4841)
• --input-file: Input JSON file path (default: opc_nodes_export.json)
• --username: Optional username for authentication
• --password: Optional password for authentication
• --security-policy: Security policy (default: None)
• --security-mode: Security mode (default: None)
• --dry-run: Validate without writing

Option B: Create nodes and write values (for Python OPC UA servers)

python create_nodes_from_export.py --input-file nodes_export.json --port 4841

This creates a new Python OPC UA server with nodes created from the export file. Nodes are created in the correct order (parents before children), then values are written.

Options:

• --input-file: Input JSON file path (default: opc_nodes_export.json)
• --port: Port to run server on (default: 4841)
• --namespace-uri: Namespace URI (default: http://examples.freeopcua.github.io)

Test Server

Run a test Python OPC UA server:

python test_server.py --port 4840

This creates a simple server with some test nodes for demonstration.

File Format

The export file is a JSON file containing:

• Node ID
• Node Class (Variable, Object, etc.)
• Browse Name
• Display Name
• Data Type
• Value (if readable)
• Access Level (if applicable)
• Children nodes (recursive structure)

Testing

Run the test suite:

# Install test dependencies
pip install -r requirements.txt

# Run all tests
pytest

# Run with verbose output
pytest -v

# Run specific test file
pytest tests/test_opc_sync.py

# Run specific test
pytest tests/test_opc_sync.py::TestOPCExport::test_export_nodes

The test suite includes:

• Export tests: Verify nodes are exported correctly with values
• Import tests: Verify values are imported and modified on destination servers
• Integration tests: Full export/import cycle with value verification

Tests use separate test servers on ports 4850 and 4851 to avoid conflicts.

Notes

• Only readable/writable nodes are exported/imported
• The tool handles hierarchical node structures
• Variable nodes with values are prioritized for import
• Object nodes are created but their values come from their child Variable nodes
• Tests automatically start/stop test servers for isolated testing