Docs · Spec · IOLink
IOLink
IO-Link — point-to-point serial communication with sensors and actuators. Two registrars (core + IODD), one enum, no DTOs.
OPC UA companion specification for IO-Link — the IEC 61131-9 point- to-point serial protocol used by sensors and actuators in industrial automation. The OPC UA side exposes IO-Link masters, their ports, and the connected devices.
What's in the package
| Artefact | Count |
|---|---|
| Enums | 1 |
| DTOs | — |
| Codecs | — |
| Registrars | 2 (IOLinkRegistrar, IOLinkIODDRegistrar) |
Two registrars:
IOLinkRegistrar— the core IO-Link specIOLinkIODDRegistrar— the IODD (IO Device Description) metadata extension
Most applications need only IOLinkRegistrar. Load IODD when
you also need access to device-description metadata exposed by
the server.
Loading
php
examples/iolink/load.php
use PhpOpcua\Client\ClientBuilder;
use PhpOpcua\Nodeset\IOLink\IOLinkRegistrar;
$client = ClientBuilder::create()
->loadGeneratedTypes(new IOLinkRegistrar()) // pulls DI
->connect('opc.tcp://iolink-master.local:4840');Direct dependencies
Notable enums
PortMode_IOLinkEnum— port operating mode (digital input, IO-Link, deactivated, etc.)
The spec's runtime surface is mostly nodes inherited from DI — identification, parameters — with IO-Link-specific extension points on top.
Last updated · 2026-05-25