OPC UA Client Overview

Introduction

The OPC Unified Architecture client (OPC UA client) allows the TM262L20MESE8T, the TM262M25MESS8T and the TM262M35MESS8T to exchange data with remote OPC UA servers.

NOTE: At least one Ethernet interface (Ethernet_1 or Ethernet_2) must be available on the controller and Ethernet traffic not blocked by the firewall.

The OPC UA client can connect with up to 5 servers concurrently. Each server can exchange 5000 items, with a maximum of 15000 items for all the servers.

Scope of the Security Model

The OPC UA client provides:

  • Support of binary message encoding

  • Support of message encryption and integrity :

    • None, Basic256 and Basic256Sha256 security policies.

    • None, Sign and Sign and Encrypt message security modes.

  • Support of user authentication:

    • None (Anonymous) or user name and password.

  • Support of user authorization:

    • To read and write value of a node.

    • To browse the information model based on the access rights of the information model, the user or the user’s role.

User and Group Access Rights

Access to OPC UA connections and data is controlled by user rights. Refer to Users Rights.

OPC UA Services

The following OPC Foundation Profiles and facets are implemented:

  • OPC UA Minimum Client Profile

    • SecurityPolicy – None

    • User Token – Anonymous Facet

    • UA-TCP UA-SC UA-Binary

    • User Token – User Name Password

  • Security Category

    • SecurityPolicy – Basic256Sha256

    • SecurityPolicy – Basic256

  • Data Access Facet

    • Attribute Read Client Facet

    • Attribute Write Client Facet

    • DataChange Subscriber Client Facet

The following functionalities are supported:

  • Attribute Services (for Value attribute only)

  • Discovery Services (Configure Endpoint only)

  • Monitored Item Services

  • Protocol and Encoding (TCP UA Binary)

  • Security

  • Session Services

  • Subscription services

  • View Services