OPC UA FX

OPC UA FX guarantees bounded low latency and jitter for time-critical automation tasks by leveraging Time-Sensitive Networking (TSN). This enables hard real-time control loops where data must arrive within microseconds. Key characteristics include:

• Isochronous data exchange synchronized to a global network clock
• Traffic scheduling to prevent collisions and ensure deterministic delivery
• Sub-microsecond synchronization across all devices on the network
• Converged network support where real-time and best-effort traffic coexist on a single wire

FX standardizes horizontal communication between PLCs and controllers without requiring a central coordinator. Using the PubSub over TSN transport profile, controllers publish DataSet messages directly onto the network, which are consumed by subscribing controllers. This replaces proprietary fieldbus protocols with an open, multi-vendor solution. Benefits include:

• Decoupled architecture where publishers and subscribers operate independently
• Peer-to-peer data sharing without routing through a supervisory system
• Hot redundancy through seamless failover between redundant controllers
• Simplified engineering with standardized connection configuration

The Connection Manager is a centralized software component that automates the configuration of TSN streams and PubSub connections across the network. It translates application-level communication requirements into network-level Quality of Service (QoS) parameters. The CM handles:

• Stream reservation and path computation through the TSN network
• Talker and Listener endpoint configuration on each participating device
• Dynamic reconfiguration when devices join, leave, or fail
• Enforcement of security policies for data integrity and device authentication

FX defines a formal Companion Specification that extends the OPC UA Address Space with types for field-level communication. This includes standardized ObjectTypes and VariableTypes for:

• ConnectionEndpoint objects representing the FX capabilities of a device
• DataSet definitions describing the structure and semantics of published data
• PubSub configuration exposed as addressable Nodes for online monitoring
• Diagnostic and status variables for network health and stream quality This semantic model enables offline engineering tools to discover and configure FX-capable devices automatically.

OPC UA FX is designed to coexist with and ultimately converge existing industrial Ethernet protocols. By mapping legacy fieldbus data models into the OPC UA Information Model, FX provides a unified semantic layer. Key convergence aspects:

• Gateway-less translation between PROFINET, EtherNet/IP, and OPC UA FX
• Shared TSN infrastructure where multiple protocols run on the same wire
• Unified diagnostics across heterogeneous device fleets
• Migration path from brownfield installations to fully converged FX networks

FX incorporates functional safety and cybersecurity as first-class architectural principles. OPC UA Safety defines a protocol layer for transmitting safety-related data over the same FX network, while the OPC UA Security Policy framework ensures:

• End-to-end encryption and message signing for all published DataSets
• X.509 certificate-based authentication for every device on the network
• Role-Based Access Control (RBAC) to restrict which controllers can subscribe to specific data
• Safety integrity levels up to SIL 3 for functional safety communication