Tools OPC UA: exam questions with worked answers

Questions for the "Tools" topic

1. Q01

   UaExpert (Unified Automation) is the reference free OPC UA client for Windows, Linux and macOS: it browses the Address Space, reads and writes values, subscribes to changes, calls Methods and manages certificates, and is an indispensable tool for any OPC UA integrator.

   TrueFalse

   7. Tools· UaExpert· Medium

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   Correct answer

   True

   Learning tip

   UaExpert covers the full feature set an integrator needs day to day. It exposes the Address Space as a tree, offers type-aware Read/Write panels, plots subscribed values on real-time graphs, lets you call Methods through auto-generated input forms, and manages the trust and rejected certificate folders directly from the UI. Plug-ins extend it with a Performance Analyzer, a History Trend View and a Data Logger. It is free for commercial use and is downloaded from unified-automation.com. Common competitors are the Prosys OPC UA Browser, the OPC UA Foundation Sample Client and the Prosys OPC UA Modeler.

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2. Q02

   node-opcua is the most popular Node.js (JavaScript) OPC UA implementation, used for fast prototyping, audit scripts and Web/MQTT/REST-to-OPC-UA integrations, and it is embedded in Node-RED and in many IoT projects.

   TrueFalse

   7. Tools· node-opcua· Medium

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   Correct answer

   True

   Learning tip

   node-opcua benefits from the native async model of Node.js, which keeps scripts short and responsive even when polling many servers in parallel. It is distributed as an NPM package, comes with extensive client and server examples, and delivers enough performance for 1 000 to 10 000 monitored items. In Python the competition is python-opcua / FreeOpcUa (deprecated) versus asyncua (the modern continuation), but the combination of Node.js with Node-RED remains one of the most productive IIoT prototyping environments available today.

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