OPC UA client

Hello All,

I have a question about the OPC UA client function of the Flexy 205.
Is it possible to have more than 3 topics for OPC UA clients ?

We have a line with multiple machines (up to 6) and they run their own opc server on the plc and we want to collect data from each machine.

Hi @Patrickje,

Unfortunately it looks like we are limited to 3 devices in the IO server for OPCUA


Dear @Tim_hms,

Is there no workaround possible allowing us to collect data from more than 3 OPC UA servers?

We have tens of Ewon Cosy’s in the field, very often with multiple machines connected to them, and are considering gradually upgrading our infrastructure to allow remote reporting using the HMS Datamailbox. A maximum of 3 OPC UA servers per Flexy would seriously complicate our plans.

Best regards,

P.S. I’m a colleague of @Patrickje.

Hi @Roelof,

I had just checked with development and unfortunately this isn’t possible to read more than 3 devices simultaneously from our device. Do they all need to be read at the same time? If not we may be able to do something with scripting.

Hi @Tim_hms,

Thank you for you quick reply.
A scripting solution sounds like a viable alternative. Our main interest is to get e.g. 5-10 KPI-like values per machine (speed, downtime, etc) with a reasonable frequency (10 minutes?) reported to the Datamailbox, and/or to a ViewON dashboard. Our largest machine-line currently has 13 machines, but more typical is 2-5.
How do you suggest a scripting solution should work?

Best regards,

What I’m thinking of right now would be to set different values of the OPCUA server through Basic

It will kind of depend on the settings that you’re using for your OPC UA devices.

The easiest way would be to use no security and anonymous authentication. Then I think we should just be able to use a script to change the Endpoint URL. But depending on how much security is on these, it may not be possible. If you’re using certificates then I’m not sure we’ll be able to do this through scripting.

If it’s the same username and password for the authentication then that would also make things pretty straight forward.


Sorry for the confusion, I just had a colleague try and change this over BASIC and this doesn’t seem to be possible. Unfortunately it looks like we are limited to 3 connections

Hi @Tim_hms,

Thank you for testing, and sorry for my late reply, I was away for a week.
You mention it is not possible using Basic, does that mean it wouldn’t be possible either using Java?

At this time, that is not something that we’re able to do. Right now the Flexy is limited to one 3 OPC UA connections regardless of Java/Javascript

That’s unfortunate, but thank you for investigating this issue.

You’re welcome, sorry that we don’t have a work around for this right now