OPC UA in the Internet of Things

The idea of connecting things other than dedicated computing devices to the Internet is by no means new. Various examples such as remotely controlled coffeemakers or refrigerators reporting their contents have circulated for several decades, but up until recently they have been little more than anecdotal in nature. However, recently there has been a clear and growing trend for ever-increasing connectivity, dubbed the Internet of Things (IoT). In essence, the idea is quite simple – connect objects and people to enable automatic communication of data without the need for human interaction. In practice of course, it requires many new technologies to implement it. Continue reading

Information modeling features in the upcoming UA SDK

Update 20.5.2014: Edited things that have changed recently.

The release of the 2.0 version of our Java SDK is just around the corner. In the new version, we are introducing new features that should help you to use information models in your UA applications. In this blog post, I will tell you about how to

  • generate Java classes from your UA models
  • create instances of UA types in your server applications
  • read instances of UA types in your client applications

Continue reading

Source for Raspberry Pi demo released

We thought that it might be useful to show how our Raspberry Pi demo is done, so here are the sources.

As stated in previous posts, the java hardware communications are made using Pi4j library.

Most of the classes are the same as in SampleConsoleServer (sample that comes with the SDK packages). Note that depending on your SDK version the classes might not compile directly (as this was done with our SDK 2.0 beta, but they should be almost the same; if they do not compile for some reason, copy them from your SDK package). The WeatherStation.java contains the IO side of the server and WeatherStationServer.java contains the UA side.

 

OPC UA 1.02

The OPC Foundation has recently released the version 1.02 of the specification and the stack components along with some sample applications and a new version of the Local Discovery Server (LDS).

Following this release we also announced the public availability of the Java SDK 2.0 Beta, which is based on the new stack. Continue reading

Raspberry Pi demo updates

Our Raspberry Pi weather station demo has been upgraded. The system has been enclosed in a box and cables have received threaded cover layer. Two DS18B20 external temperature sensors have been added, one of them can be removed if needed (by a DB9 connector, with custom soldering). Three buttons have been added for adding interaction for exhibition visitors. Continue reading

Developing OPC UA for Android

I thought I’d share a few pointers about developing OPC UA on Android, since our Prosys OPC UA Java SDK has supported Android from version 1.3 onwards. In recent times we’ve had a surge of interest from Android users, who have helped us in understanding some typical use cases of developers on mobile platforms. In this vein, we’ve already shared some of our Android development effort in the form of our Christmas special that was available for a limited time as a preview for our full Android client. It allowed connecting to a Beckhoff programmable logic in our office via OPC UA (the PLC is running Beckhoff’s OPC UA server for Windows CE) and controling a signal light column, which was viewable via a webcam. Continue reading

OPC UA Sessions, Subscriptions and Timeouts

In this article I will try to clarify all the various parameters of OPC UA communications, especially related to the various timeouts that are available.  They provide a flexible means to control the connection between the UA client and server, both on the client and server side, but it is not always very clear which parameter is which and what is the actual effect of each. Continue reading