---
description: Apply the OPC UA Standard to automated workcells, hybrid stations, and shared OPC UA server deployments.
alias: userguide-equipment-integration-opcua-standard-integration-patterns
---

# Integration Patterns

This page brings together the recurring station and deployment patterns supported by the standard. The underlying OPC UA structure and feature contracts remain the same; the initiation path, Material-resolution policy, and server topology vary by implementation.

## Industry Use Cases

The standard is industry-neutral. The actual recipe and process-data parameters vary by machine and process, while the operation handshake and functional folders remain reusable.

| Pattern                                       | Typical examples                                   | Key design concern                                                     |
| --------------------------------------------- | -------------------------------------------------- | ---------------------------------------------------------------------- |
| [Automated Workcell](#automated-workcell)     | Assembly, filling, test, packaging, machining      | Deterministic machine requests and acknowledgements                    |
| [Hybrid Station](#hybrid-station)             | Manual assembly, inspection, repair, assisted work | Operator- and machine-initiated paths must converge without duplicates |
| [Shared OPC UA Server](#shared-opc-ua-server) | Line gateway, cell server, edge aggregation        | Unique Resource base nodes and profile resolution                      |

## Automated Workcell

Typical examples include assembly cells, filling machines, test equipment, packaging machines, and machining centers.

```mermaid
--8<-- "docs/userguide/equipmentintegration/opcua-standard/_includes/mermaid-sequence-theme.txt"
sequenceDiagram
    participant M as Machine
    participant I as Connect IoT
    participant E as MES

    M->>I: Payload + MachineOperationRequest
    I->>E: Execute MES operation
    E-->>I: Operation performed within transaction
    I->>M: MESOperationPerformed
    M-->>I: MachineOperationConfirmed
    I-->>E: Machine confirmed
    E->>E: Commit transaction
```

### Design Rules

- Use explicit Material identity where possible.
- Permit FIFO only when queue behavior is deterministic and approved.
- Treat machine request edges as triggers, not repeated commands.
- Download recipes before signaling **Track In** completion when recipe delivery is mandatory.
- Post process readings at defined points in the machine cycle.
- Make state values stable enough to avoid excessive transitions.

### Example Parameters

A fastening cell might expose recipe values such as `TorqueTarget` and `AngleTarget`, then post `AppliedTorque`, `AppliedAngle`, `CycleTime`, and `Result`. These names are examples; the actual MES model defines the contract.

## Hybrid Station

Hybrid stations are common in manual assembly, inspection, rework, loading, and assisted-equipment processes.

```mermaid
flowchart LR
    O("Operator") --> U("MES UI")
    U --> E("MES Operation")

    M("Machine") --> I("Connect IoT")
    I --> E

    E --> R("Operation performed<br/>within transaction")
    R --> I

    I --> P("MESOperation<br/>Performed")
    P --> M

    M --> C("MachineOperation<br/>Confirmed")
    C --> I
    I --> E
    E --> K("Commit MES<br/>transaction")

    classDef standard fill:#FFFFFF,stroke:#64748B,color:#334155,stroke-width:1.5px;
    classDef secondary fill:#FFFFFF,stroke:#CBD5E1,color:#64748B,stroke-width:1.5px;
    classDef highlight fill:#075C00,stroke:#075C00,color:#FFFFFF,stroke-width:1.5px;

    class O,U,M,I,E standard;
    class R,P,C,K secondary;

    linkStyle default stroke:#94A3B8,stroke-width:1.5px;
```

### Design Rules

1. Operator initiation is Operator → MES UI → MES operation; the UI does not write OPC UA nodes.
2. Machine initiation is Machine → Connect IoT → MES operation.
3. Both paths start the normal performed/confirmed handshake after MES performs the action within its transaction.
4. The machine must consume `MESOperationPerformed` even when `MachineOperationRequest` is false.
5. Correlation and runtime state must prevent the operator and machine from executing the same operation twice.
6. The UI and machine should clearly show pending, successful, rejected, and missing-acknowledgement states.

## Shared OPC UA Server

A line gateway or edge **OPC UA Server** can expose multiple machine Resource trees. Several Resources can therefore share connection settings while retaining independent base nodes, subscriptions, and controller behavior.

Profile selection and completeness are defined only in [Configure the OPC UA Connection](../configuration/opcua-connection.md#profile-selection-rule). For this use case, focus on the design consequences of sharing a server.

### Design Rules

1. Each Resource has a unique Base NodeId.
2. Size OPC UA sessions, subscriptions, and the **Automation Manager** deployment for the combined node and update load.
3. Restrict credentials and access rights to those required by each integration.
4. Assess whether one server outage can interrupt several Resources and define the corresponding recovery procedure.

### Validation

- [ ] Each Resource resolves its intended base node.
- [ ] Two Resources do not unintentionally point to the same machine node tree.
- [ ] Subscription and update load remains within the approved server and runtime capacity.