topic Reading value from OPC UA Server in FlexSim Forum

Reading value from OPC UA Server

sakamoto_ryosuke — Tue, 05 Sep 2023 08:54:44 GMT

[ FlexSim 23.0.9 ]

Hello, one of our customer is trying to connect between FlexSim and PLC using OPC UA. Customer succeeded in sending value from FlexSim to OPCUA. However, unable to read value from OPCUA. In version 2022, I think we needed to make check on "Subscribe to Changes" in order to read value from OPC UA. However, it has been grayed out in 2023.

Do you need not make check on this? What have changed in 2023 from 2022?
There is no error message from FlexSim or OPC Server.

Re: Reading value from OPC UA Server

lcavallero — Tue, 05 Sep 2023 13:40:02 GMT

Hi,

In 2023 OPC UA connection are create with the "Poll for changes" activate, by default:

This option disable the "Subscribe for changes".
The "Poll for changes" has been introduced to by-bass the minimum publishing time of OPC UA servers that some time can be also >200ms.

Re: Reading value from OPC UA Server

sakamoto_ryosuke — Wed, 06 Sep 2023 23:53:35 GMT

@Luciano Cavallero Thank you for your reply. To clarify, my understanding is that subscribe for change and poll for changes are functionally same. Poll for changes give you better performance?

Re: Reading value from OPC UA Server

lcavallero — Thu, 07 Sep 2023 10:04:05 GMT

Yes.

We introduced the "poll for changes" to overcome minimum publishing time imposed by some OPC UA Server.

Re: Reading value from OPC UA Server

Jeanette_Fullmer — Tue, 12 Sep 2023 17:53:40 GMT

Hi @Ryosuke S, was Luciano Cavallero's answer helpful? If so, please click the "Accept" button at the bottom of their answer. Or if you still have questions, add a comment and we'll continue the conversation.

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