Axel: Document optional OPC Classic Gateway for Windows

2026-08-17T10:46:45Z

Document optional OPC Classic Gateway for Windows

New page

{{DISPLAYTITLE:IBH OPC UA: OPC Classic Gateway}}
The optional '''OPC Classic Gateway''' exposes the address space of the 64-bit IBH OPC UA Server as OPC Data Access 2.0/3.0. It is available exclusively in the Windows version. Linux and DCOM on Linux are not supported.

== How it works ==
The gateway runs in the existing 64-bit <code>ibhopcua</code> service. OPC Classic is connected through a COM out-of-process server. Both 32-bit and 64-bit OPC Classic clients can therefore access the server.

The gateway address space is built from the OPC UA <code>Objects</code> folder. Read and write operations are mapped internally to the corresponding UA NodeIds. UA value, timestamp and status are converted to OPC DA value, timestamp and quality.

== Setup options ==
The Windows installer provides three installation levels:

# OPC UA only
# OPC UA with a local OPC Classic DA Gateway
# OPC UA with OPC Classic and remote DCOM access

The Classic feature installs the OPC Foundation Core Components for x86 and x64 as well as OPCEnum. No additional commercial OPC library is required. The selection can later be changed through '''Settings / Apps / Installed apps / Modify'''.

Gateway registration:

{| class="wikitable"
! Entry
! Value
|-
| ProgID
| <code>IBHsoftec.IBHLinkUA.OPCDA.1</code>
|-
| version-independent ProgID
| <code>IBHsoftec.IBHLinkUA.OPCDA</code>
|-
| CLSID
| <code>{624D95B5-296C-48AD-9543-987FE007838A}</code>
|}

== Web configuration ==
When the Classic feature is installed, the '''OPC Classic Gateway''' page appears in the Web Configurator. The gateway can be enabled or disabled there. If the remote setup option was installed, remote DCOM can also be enabled or disabled.

Changes take effect after the IBH OPC UA service is restarted. Runtime configuration cannot exceed the feature scope selected by the administrator during setup.

== Remote DCOM ==
Remote mode configures DCOM Packet Integrity and permits launch, activation and access only for authenticated users, administrators and the local system. Anonymous access is not enabled.

The installer creates the following inbound Windows Firewall rules:

* application-specific rule for <code>IBHOpcUa.exe</code>
* TCP 135 for the RPC Endpoint Mapper

External firewalls must additionally allow the dynamic RPC ports used by Windows. Alternatively, the RPC port range can be restricted administratively.

For reliable authentication, client and server should be members of the same domain or mutually trusted domains. In workgroups, matching Windows accounts and passwords must exist on both computers.

== Client requirements ==
The client computer requires the OPC Core Components for its architecture. These are normally included with the OPC Classic client installation.

Changes to the OPC UA address-space structure are reflected in the OPC Classic Gateway after the service is restarted.

== Related pages ==
* [[IBH OPC UA|IBH OPC UA overview]]
* [[IBH OPC UA:Installation on Windows|Installation on Windows]]
* [[IBH OPC UA:Startup operations|Startup and commissioning]]

[[Category:IBH OPC UA]]
[[Category:OPC Classic]]

IBH OPC UA:OPC Classic Gateway - Revision history

Axel: Document optional OPC Classic Gateway for Windows