How to call an OPC UA method?

#1

How do I call a method of an object served by an OPC UA server?
The python scripting library supports sys.opc.read/write but I could not find anything for calling an object method/procedure.
Thanks for your help, Patrick

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#2

There’s no support for this right now. It’s among the many OPC-UA related improvements that are coming down the road, however.

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#3

There is a python client for OPC UA, called pyUAF. Would it be possible to import this in a python script? IN other words, in a python script that is defined in an Ignition project, can I import 3rd party libraries?

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#4

Yes, you can import 3rd party Python libraries into Ignition. See here: perfectabstractions.com/blog … on-modules

Best,

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#5

Yes, you can import some python libraries like Nick mentioned, but this one likely won’t work because it’s just python bindings to a C/C++ library. You’ll have to try it to be sure though.

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#6

Sorry for reincarnating an older thread, but I was wondering if there was ever a solution produced for this problem?

I realize that I.A. wrote the OPC stack themselves, and didn’t implement the method service initially. Do you have a time frame when that service would be done? Can it be done in a similar way to the SOAP service method calls?

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#7

[quote=“BillS”]Sorry for reincarnating an older thread, but I was wondering if there was ever a solution produced for this problem?

I realize that I.A. wrote the OPC stack themselves, and didn’t implement the method service initially. Do you have a time frame when that service would be done? Can it be done in a similar way to the SOAP service method calls?[/quote]

The OPC-UA client in Ignition 7.8 will be able to call methods.

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#8

Thank you for the fast reply. What is the release schedule for 7.8?

What about the implementing in a driver for the OPC-UA server side, is that also going to be in 7.8?

I’m in the process of trying to write a driver for a EDM device that has a custom socket based communication stack using XML for the messaging. I have test java client code working, and am now attempting to move that into an Ignition driver. I’m using Netty for the TCP and UDP I/O and XStream for the XML parsing.

I need to implement methods for opening and closing doors, loading, selecting, starting, stopping, pausing, resuming, … jobs.

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#9

[quote=“BillS”]Thank you for the fast reply. What is the release schedule for 7.8?

What about the implementing in a driver for the OPC-UA server side, is that also going to be in 7.8?

I’m in the process of trying to write a driver for a EDM device that has a custom socket based communication stack using XML for the messaging. I have test java client code working, and am now attempting to move that into an Ignition driver. I’m using Netty for the TCP and UDP I/O and XStream for the XML parsing.

I need to implement methods for opening and closing doors, loading, selecting, starting, stopping, pausing, resuming, … jobs.[/quote]

Ignition 7.8 is going to be released around the same time as our community conference - late September.

Support for methods in the server/driver API (or any new functionality at all, for that matter) won’t happen until 7.9, where the server implementation and driver API are being replaced entirely by a new implementation.

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