Mobile access to measurement applications is no longer just a nice addition. It’s expected. The worldwide permeation of mobile devices has given people unlimited and instant access to information. Mobile technology has created a natural expectation to receive continuous access to information and is now influencing the test and measurement market.
Engineers and scientists are creating systems that can be accessed through mobile devices. These systems alert technicians when tests are complete and provide the ability to change data on the go. Mobile technology is evolving quickly, making implementation and setting standards difficult. To capitalize, engineers and scientists must evolve their skill sets by understanding options for mobile integration and keeping tabs on the outlook for future mobile systems.
Mobile technology is a relatively new addition for measurement systems, but common solutions are starting to evolve. The most basic solution is using a mobile device to take handheld measurements. Another is to use the mobile device as a human machine interface (HMI) for remote measurement systems.
Handheld Measurements
The idea of handheld measurement devices isn’t new. Handheld digital multimeters have been around for years along with a host of other handheld measurement devices on the market. Overall, these devices are created for a specific purpose. However, the evolution of the technology behind mobile devices provides the opportunity to create more flexible and reliable handheld measurement devices.
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Mobile devices and their operating systems use powerful platforms, giving application developers access to hundreds of thousands of apps so they can customize and create in these platform environments. Companies are now creating measurement devices that can be plugged directly into mobile devices. Native apps created by the measurement hardware manufacturer can interact with the plug-in device to read data. In addition, if the manufacturer used an open standard for data transfer, app developers could create apps to interact with the plug-in hardware and give the user a completely different experience.
Engineers should consider the interface when choosing a mobile plug-in measurement. Common interface standards like USB should be the primary consideration for these measurement systems. Proprietary interfaces are riskier when creating a measurement system that needs to be supported for a number of years. Hardware manufacturers that use proprietary interfaces could change them in future releases with no warning.
Other than directly connecting to mobile devices, wireless measurement devices are also a good solution for handheld measurements. New data acquisition devices are being created that have built-in wireless capabilities and can be accessed from mobile devices or traditional PCs. One mobile device can take a measurement from many wireless measurement devices. Native apps or software integrated development environments (IDEs) can be used to program these wireless measurement devices. As measurement systems increasingly need more flexibility, engineers can expect measurement device manufacturers to release more wireless measurement devices.
Remote HMI
There are a lot of options to consider when adding a remote HMI to a measurement system. One of the first considerations is how to communicate between the measurement system and the HMI. Standard network protocols like TCP or UDP can be used, but a growing trend is to use a technology built on TCP and HTTP called web services.
A web service is an application programming interface (API) that can be accessed via HTTP requests. When called, web services return a human-readable response. Modern web services use JavaScript Object Notation (JSON) responses, but XML, HTML, and plain text are other response options. Engineers and scientists then can program nice interfaces that render the web service response as something more visually pleasing, such as a waveform graph.
There are several reasons why engineers and IT departments are choosing web services over other communication technologies. First, web services are straightforward and simple to access from any programming language, including C++, Objective C, and LabVIEW. Second, since web services sit on top of common network protocols, the communication is considered “IT friendly” compared with proprietary network protocols. Third, web services can be encrypted easily via industry-standard technologies like Secure Sockets Layer (SSL) or Transport Layer Security (TLS).
Another consideration is how to view the data communicated from the measurement system. Many different technologies can be used to create a data client. The graphical user interface (GUI) enables users to view or control the measurement data being transmitted from the measurement system. A standard browser can send HTTP requests to the web service. Using HTML and Javascript, a data client can be created to view the returned data on a graph instead of just XML.
Building a custom data client that uses a browser provides the flexibility to customize the look and functionality while using technologies that don’t require an extra run-time engine to operate. HTML is also cross-platform compatible so one data client could be created that would be supported on multiple operating systems. Another alternate to HTML would be to create native apps that run on specific mobile operating systems.
Native apps provide better performance and usability than web-based (HTML) apps. A caveat is that native apps need custom development for each mobile operating system. Apps written for Android, for example, need to be ported to iOS. HTML5 is promising because it is supported across most operating systems, but the technology is still quite young. Notably, Facebook switched from an HTML5 app to native apps after performance and usability complaints were heaped on its HTML5 app. HTML5 is quickly improving performance on mobile operating systems, so hope still exists that the technology will be a more viable option in the near future.
The first step to creating a remote HMI for a measurement system is choosing how to transmit the measurement data and which data client technology to standardize on. Engineers are learning more about what options are available for creating remote HMI solutions, and this functionality has become a primary consideration in measurement system platform choice.
Mobile Security
The more mobile devices connect to secure information, such as bank accounts or private company data, the more they become the target of hackers. Malware, software aimed at disrupting computer operations, has risen exponentially over the past few years in mobile operating systems (see “Spammers Launch 350k Mobile Variants In 2012” at mobiledevdesign.com). Symantec, a global security software company, lists “mobile attacks” as one of the top five trends to watch out for in 2013. As engineers are adding mobile technology to their measurement systems, mobile security needs to be a primary concern.
To combat mobile security threats, download apps only from official app stores and use anti-virus software apps on your mobile devices. Most manufacturers offer steps that enhance security for their mobile devices. Engineers should look into the specific security detail for their mobile devices and add necessary security measures. Simple steps such as requiring a login or pin code access and turning on “remote-wipe” services, so you can erase all information on your device if it gets stolen or lost, can help mitigate some risks.
The rise of enterprise app stores will also assist in mobile security in the workplace. Mobile operating-system providers now make it possible for companies to create their own internal app stores with company-approved apps. This is a great way for IT departments to distribute apps that access company databases as well as push suggested mobile apps like anti-virus protection.
Mobile’s Future In Test and Measurement Systems
Data acquisition systems of the future will continue to become more networked. Mobile access is becoming a primary requirement for test and measurement systems, and engineers are future-proofing those systems now. Engineers and scientists must improve their skill sets by understanding options for mobile integration and keeping tabs on the outlook for future mobile systems.
Richard McDonell is the director of Americas technical marketing at National Instruments. He joined National Instruments with a BSEE in 1999 and led in the successful adoption of NI TestStand test management software and PXI modular instrumentation while serving as an industry leader in the test engineering community through many technical presentations, articles, and whitepapers. His specific technical focus areas include modular test software and hardware system design, parallel test strategy, and instrument control bus technology. He holds a bachelor’s degree in electrical engineering from Texas A&M University.