I was looking into options of OPC UA client for ios and Android. I found out that there are some solutions available natively in android and iOS
Does anyone have idea on "QT mobile" in this regard ? Does QT have any inbuilt support for "OPC UA" . I could not find much details on this topic as the information about QT mobile is limited.
“QtOpcUa currently focuses on functionality needed to create OPC UA enabled HMIs. It offers a Qt API for a subset of the OPC UA specification by wrapping an existing OPC UA stack. This approach allows to choose the right stack for the given project while always working with the same Qt API.” Please refer to https://blog.basyskom.com/2015/introducing-qtopcua/ and ——https://github.com/qt/qtopcua for more details.
There is not yet inbuilt support for OPC UA on QT Mobile.
There is port of OPC UA ANSI C Stack to iOS. and you can use OPC UA Java Stack for Android development.
Since Qt5.11 there is Qt OPC UA which is an official Qt module. It currently (Dec. 2018) is still a tech preview, but aims to become a fully stable module in 5.13 (Mid. 2019).
Qt OPC UA is not a complete stack but a standard API for Qt with the goal of making it easy to interact with OPC UA devices/services from within Qt. In the background Qt OPC UA relies on an OPC UA SDK. There are currently two plugins (Unified Automation and open62541).
Qt OPC UA is either part of Qt for Automation (then you need a license) or is available as a regular tripple licensed Qt module. Qt OPC UA only ships with the official installer if you have a Qt for Automation license. If you don't you need to compile it yourself. See here how to do it: https://blog.basyskom.com/building-qt-opc-ua-with-open62541/.
I have already successfully used Qt OPC UA with the open62541-backend on Android and iOS.