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OPC UA Receiver Connector

The OPC UA Receiver Connector allows reading data from OPC UA server nodes, enabling real-time monitoring and data collection from industrial automation systems and IoT devices.

Service Description​

The OPC UA Receiver Connector enables reading values from OPC UA server nodes. It establishes a secure connection to the OPC UA server, authenticates, and reads data from specified nodes at configured intervals.

Required Connector Properties​

  • Host: The OPC UA server endpoint URL (e.g., opc.tcp://localhost:4840)
  • Anonymous Login: Enable anonymous authentication (true/false)
  • Basic Authentication ID: Credential ID for username/password authentication
  • Allowed Security Policies: Security policy to use (None, Basic128Rsa15, Basic256, Basic256Sha256)
  • Key Alias: Certificate key alias for certificate-based authentication
  • Key Store ID: Key store containing the client certificate
  • Application URI: Unique identifier for the OPC UA client application
  • Application Name: Descriptive name for the OPC UA client
  • Node IDs: Comma-separated list of OPC UA node identifiers to read from
  • Data Type: Data type of the values to read (Boolean, Int32, Double, String, etc.)

Configuration Details​

Connection Settings​

  • Host: Full OPC UA endpoint URL including protocol (opc.tcp://)
  • Application URI: Should be unique and match certificate if using certificate auth
  • Application Name: Identifies your application in OPC UA server logs

Authentication​

Choose one of the following authentication methods:

Anonymous Login​

  • Set Anonymous Login to true
  • No credentials required (use only in trusted networks)

Username/Password Authentication​

  • Set Anonymous Login to false
  • Configure Basic Authentication ID with credential reference
  • Credentials must be pre-configured in Operations → Credentials

Certificate-based Authentication​

  • Set Anonymous Login to false
  • Configure Key Store ID with keystore reference
  • Configure Key Alias with certificate alias
  • Certificate must be pre-configured in Operations → Keystores

Security Policy​

Select appropriate security policy:

  • None: No encryption (use only for testing)
  • Basic128Rsa15: RSA 1024-bit encryption (legacy)
  • Basic256: RSA 2048-bit encryption
  • Basic256Sha256: RSA 2048-bit with SHA-256 (recommended)

Node Configuration​

  • Node IDs: Specify OPC UA node identifiers to read (e.g., ns=2;s=MyDevice.Temperature)
    • Format: ns=<namespace>;s=<identifier> or ns=<namespace>;i=<numeric>
    • Multiple nodes: ns=2;s=Temperature,ns=2;s=Pressure,ns=2;s=Status
  • Data Type: Expected data type of the nodes

Supported Data Types​

  • Boolean: true/false values
  • Byte, SByte: 8-bit integers
  • Int16, UInt16: 16-bit integers
  • Int32, UInt32: 32-bit integers
  • Int64, UInt64: 64-bit integers
  • Float: 32-bit floating point
  • Double: 64-bit floating point
  • String: Text values
  • DateTime: Timestamp values

Message Flow​

  1. OPC UA Receiver initiates connection to OPC UA server (based on polling schedule)
  2. Authenticates using configured method
  3. Reads values from specified OPC UA nodes
  4. Receives node values and metadata
  5. Formats data into message body
  6. Passes message to next integration step
  7. Maintains or closes connection based on configuration

Polling Configuration​

The OPC UA Receiver typically operates on a polling schedule:

  • Configure polling interval in the process start connector
  • Use cron expressions for scheduled reads
  • Consider server load when setting polling frequency

Best Practices​

  1. Use Secure Policies: Always use encryption in production (Basic256Sha256)
  2. Certificate Authentication: Prefer certificate-based auth over username/password
  3. Validate Node IDs: Ensure node IDs exist and are readable on the server
  4. Optimize Polling: Set appropriate polling intervals to balance freshness and load
  5. Handle Errors: Implement error handling for connection and read failures
  6. Monitor Quality: Check OPC UA quality codes in responses
  7. Batch Reads: Read multiple nodes in single request for efficiency
Usage

Use the OPC UA Receiver Connector when you need to collect real-time data from industrial equipment, monitor sensor values, or integrate with SCADA systems. Common scenarios include reading temperature sensors, pressure gauges, production counters, or equipment status.

Message Format​

The connector outputs data in the following format:

{
  "timestamp": "2024-03-04T10:25:00Z",
  "nodes": [
    {
      "nodeId": "ns=2;s=MyDevice.Temperature",
      "value": 25.5,
      "dataType": "Double",
      "quality": "Good",
      "sourceTimestamp": "2024-03-04T10:25:00Z"
    },
    {
      "nodeId": "ns=2;s=MyDevice.Status",
      "value": "Running",
      "dataType": "String",
      "quality": "Good",
      "sourceTimestamp": "2024-03-04T10:25:00Z"
    }
  ]
}

Quality Codes​

OPC UA provides quality codes for each value:

  • Good: Value is valid and reliable
  • Uncertain: Value may not be accurate
  • Bad: Value is invalid or unavailable

Always check quality codes before processing values.

Error Handling​

Common errors and solutions:

  • Connection Failed: Verify host URL and network connectivity
  • Authentication Error: Check credentials or certificate configuration
  • Security Policy Mismatch: Ensure policy matches server requirements
  • Node Not Found: Verify node ID exists on the server
  • Access Denied: Check user permissions for reading nodes
  • Data Type Mismatch: Ensure expected type matches actual node type
  • Certificate Error: Verify certificate validity and trust
  • Timeout: Increase timeout or reduce number of nodes per read

Integration Example​

A typical integration flow using OPC UA Receiver:

  1. Timer/Scheduler: Triggers the flow at regular intervals
  2. OPC UA Receiver: Reads sensor data from OPC UA server
  3. Converter: Converts OPC UA data to JSON/XML
  4. Filter: Filters based on quality codes or value thresholds
  5. Mapping: Maps to business data format
  6. Database/API: Stores or forwards processed data
  7. Alert: Sends alerts if values exceed thresholds

Subscription Mode (Advanced)​

For real-time data changes, OPC UA supports subscriptions:

  • Server notifies client when values change
  • More efficient than polling
  • Requires persistent connection
  • Configure subscription parameters in advanced settings