Re: EPICS OPCUA Module build

[Ralph Lange via Tech-talk <tech-talk at aps.anl.gov>]

The open62541 SDK low-level client needs to be built first, via its own CMake/make process.
(The documentation has the cmake command line to use for that.)

The dependencies for the low-level client need to be installed first.
Last not least there is an open PullRequest [1], adding a script that promises to simplify building of the open62541 SDK on Windows. I haven't properly tested that PR yet.

Then, the OPCUA module build needs to be configured by adding a single configuration file that shows the location and the settings of the low-level library. (That file is also shown in the documentation.) With that configuration (and the open62541 libraries in place), the Device Support module will build.

Then you need to build your application, which builds the IOC. That application only needs the location of the OPC UA Device Support module, where it will find the low-level client config.

There's also an example IOC application that automatically gets built with the Device Support module. To use that, you have to cd into it and start it.

Cheers,
~Ralph

[1] https://github.com/epics-modules/opcua/pull/185

On Tue, 23 Jun 2026 at 14:46, Luis Alberto De Sousa Moreira <luis.moreira at epfl.ch> wrote:

Hi Ralph,

All of it I think.

I cloned the opcua module and downloaded the open62541 files. The issue I have is how to tell make what files to use and where to get them from.

I'm on the OPCUA folder what do I need to do for it to build the open62541 client and then move on to build the OPCUA module?

Is it on the make file or in the configuration?

Kind Regards

       Luis