README

Modern, production-ready OPC UA (Unified Architecture) client library for PHP 8.4+. This library is a PHP implementation of OPC UA client functionality based on the architecture and design of the OPC Foundation UA-.NETStandard implementation. While maintaining wire-protocol compatibility and following the same design patterns, this is an independent implementation adapted for PHP 8.4+ with full type safety and modern language features.

Features

• Complete OPC UA Client Implementation

  • Binary protocol (opc.tcp://) with full UA services
  • Secure channel with encryption (Basic256Sha256)
  • Session management with automatic reconnection
  • Certificate-based authentication

• High-Level API

  • Fluent ClientBuilder for easy configuration
  • Browse address space with filtering
  • Read/write nodes with type safety
  • Subscriptions and monitored items
  • Event monitoring and alarms

• Performance Optimizations

  • LRU caching for node metadata
  • Automatic batch splitting for large operations
  • Server capability detection
  • Connection pooling ready

• Production Ready

  • PSR-3 logging integration
  • Comprehensive error handling
  • Type-safe throughout (PHP 8.4 strict types)
  • PHPStan level 9 compliant
  • Extensive test coverage

Quick Start

Installation

composer require techdock/opcua

Basic Usage

<?php

use TechDock\OpcUa\Client\ClientBuilder;
use TechDock\OpcUa\Core\Types\NodeId;

// Connect to server
$client = ClientBuilder::create()
    ->endpoint('opc.tcp://localhost:4840')
    ->withAnonymousAuth()
    ->build();

// Read a value
$serverTime = $client->session->read([NodeId::numeric(0, 2258)])[0];
echo "Server time: {$serverTime->value}\n";

// Browse nodes
$objectsFolder = NodeId::numeric(0, 85);
$references = $client->browser->browse($objectsFolder);

foreach ($references as $ref) {
    echo "- {$ref->displayName->text}\n";
}

// Clean up
$client->disconnect();

With Performance Features

$client = ClientBuilder::create()
    ->endpoint('opc.tcp://production-server:4840')
    ->application('My App', 'urn:mycompany:app')
    ->withUsernameAuth('operator', 'password')
    ->withCache(maxSize: 5000, ttl: 600.0)  // 10min cache
    ->withAutoBatching()                     // Auto-split large requests
    ->operationTimeout(60000)                // 60s timeout
    ->build();

Monitoring Data Changes

// Create subscription
$subscription = $client->session->createSubscription(
    publishingInterval: 1000.0,  // 1 second
);

// Monitor a node
$nodeId = NodeId::numeric(2, 1001);
$subscription->createMonitoredItem(
    nodeId: $nodeId,
    samplingInterval: 500.0,
    callback: function ($value, $timestamp) {
        echo "Value changed: {$value} at {$timestamp}\n";
    }
);

// Process notifications
while (true) {
    $subscription->publishAsync();
    usleep(100000); // 100ms
}

Documentation

• Getting Started - Installation and first steps
• ClientBuilder Guide - Configuration API reference
• Browsing - Exploring the address space
• Reading & Writing - Data operations
• Subscriptions - Real-time data monitoring
• Security - Certificates and authentication
• Performance - Optimization strategies
• API Reference - Complete API documentation
• Examples - 20+ working examples

Requirements

• PHP 8.4 or higher
• ext-sockets - Socket communication
• OpenSSL support - For secure connections

Supported Features

Architecture

┌─────────────────────────────────────────┐
│         ClientBuilder (Fluent API)      │
├─────────────────────────────────────────┤
│  ConnectedClient                        │
│  ├─ Session (Service Calls)             │
│  ├─ Browser (Address Space)             │
│  └─ Cache (Optional)                    │
├─────────────────────────────────────────┤
│  Core Protocol Layer                    │
│  ├─ SecureChannel (Encryption)          │
│  ├─ BinaryEncoder/Decoder               │
│  └─ TcpConnection                       │
└─────────────────────────────────────────┘

Testing

# Run all tests
composer test

# Run with coverage
composer test-coverage

# Static analysis
composer analyse

# Code style
composer cs-check
composer cs-fix

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

Security

For security vulnerabilities, please see SECURITY.md.

License

This project is licensed under the MIT License - see LICENSE file for details.

For complete attribution and licensing information, see NOTICE.

Credits

Developed by TechDock

Attribution

This library is a PHP implementation of OPC UA client functionality based on the architecture and design of the OPC Foundation UA-.NETStandard implementation. The original C#/.NET implementation provides the architectural foundation and design patterns for this PHP adaptation.

Original Project:

• Repository: OPCFoundation/UA-.NETStandard
• License: Dual-license (RCL for OPC Foundation members, GPL 2.0 for non-members)
• Copyright: OPC Foundation

This PHP Implementation:

• Scope: Client-only implementation (no server functionality)
• Approach: Independent implementation following the same architectural patterns
• Protocol: 100% wire-compatible with OPC UA binary protocol specification
• Code: Adapted to PHP 8.4+ idioms, type system, and modern language features
• Size: Approximately 35-40% of the .NET core stack code volume
• License: MIT License (as an independent implementation)

Key Differences:

• Client-only (UA-.NETStandard includes both client and server)
• Hand-written message classes (vs. code-generated from XML schemas)
• Focused on core client features (Browse, Read, Write, Subscribe, Call)
• PHP-native approach using readonly classes, union types, and match expressions

We are deeply grateful to the OPC Foundation and the UA-.NETStandard contributors for their excellent reference implementation that made this PHP client possible.

Special thanks to:

• The OPC Foundation for the OPC UA specification and reference implementations
• The UA-.NETStandard development team for their well-architected codebase
• All contributors to open-source OPC UA projects

See NOTICE for complete attribution and licensing details.

Resources

• OPC Foundation
• OPC UA Specification
• UA-.NETStandard (Original Implementation)
• Unified Architecture

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Email: info@techdock.ch