Smartphones and Tablets for Measurement and Control

Publish Date: Nov 18, 2014 | 42 Ratings | 4.40 out of 5 | Print | 12 Customer Reviews | Submit your review

Table of Contents

  1. Remote Measurement and Control
  2. Portable Measurements
  3. NI Tools for Mobile Devices
  4. Next Steps

Every day we see more and more people with an iPhone, Android-based phone, or other smartphone. According to Gartner Research, worldwide smartphone sales reached 472 million units in 2011, which is a 58 percent increase over 2010. Smartphones are growing in popularity and changing the way we live our lives. We no longer memorize phone numbers because we carry a phonebook in our pockets. We rarely ask for driving directions because smartphones include GPS with maps. We are connected 24/7 through email, text messaging, and now even video chat. Smartphones provide instant access to information wherever we go.

Figure 1. Nearly 500 million smartphones were sold in 2011.

There’s another game changer on the horizon—tablets. Forrester Research predicts that by 2013 tablets will outsell desktop computers in the US. Tablets are somewhere between a smartphone and a laptop. They are web-connected with touch-screen interfaces like smartphones, but they feature the screen real estate of laptops. The first to release and start gaining adoption, was the Apple iPad; however, other big players like Google, Microsoft, Samsung, HP, Amazon, and RIM have announced devices and OSs of their own. Like smartphones, tablets are poised to disrupt the traditional ways we complete common tasks. With the iPad, for example, we can intuitively download and read books, stream television shows, or read magazines and newspapers. As the technology continues to evolve and prices drop, it’s only a matter of time before tablets become more widely adopted.

Figure 2. Researchers predict tablets will outsell desktop computers in the US by 2013.

We often consider smartphones and tablets recreational devices for playing games and streaming videos, but they can also be powerful engineering tools. Desktop PCs and laptops, for example, are commonly used for simple tasks like Internet browsing, word processing, and gaming. But they are also one of the most important tools engineers use for designing, validating, and producing products. Engineers use PCs to take measurements, store data, automate tests, perform analysis, create reports, and much more. The extreme portability and web connectivity of smartphones and tablets make them exciting recreational devices, but these features also present interesting use cases for measurement and control applications. Smartphones and tablets offer engineers a way to remotely measure and control systems and a new platform for portable measurements.

1. Remote Measurement and Control

As more of us adopt smartphones, wireless carriers are building an infrastructure to provide Internet access to these devices from virtually anywhere. This infrastructure not only offers us access to email, sports scores, and news, it also gives engineers a vehicle for accessing measurement data from anywhere. Engineers can carry a smartphone or tablet and essentially have, right in their pockets, a human-machine interface (HMI) for remotely viewing and controlling systems. They can monitor data for trends, view historical data over periods of time, instantly receive alarms based on measurements, or remotely control an application or test sequence.

Machine condition monitoring (MCM) is a potential application for these use cases. The most primitive form of evaluating a machine’s condition is through manual test or even just visual inspection. MCM aims to automate this process by continually monitoring a machine’s performance to predict when a failure might occur so that it can be repaired when it is most cost-effective. In many cases, the cost of a machine failure involves more than just replacing parts. There are also added costs to machine downtime. This makes it important to notify engineers as soon as possible so they can diagnose the problem. Smartphones and tablets can provide this instant notification of a failure. By viewing live measurements with a smartphone or tablet, an engineer can even potentially diagnose the problem remotely.

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2. Portable Measurements

Because of their network connectivity, smartphones and tablets are great tools for remotely viewing measurements; however, their small size and processing power also make them effective for portable measurements. For portable measurements today, engineers can choose from several options such as handheld meters and portable data loggers with integrated displays. But these typically have fixed functionally that is defined by the vendor. Smartphones and tablets can offer a more flexible solution. In the future, engineers may be able to directly connect a data acquisition (DAQ) device and write software specifically for their application needs.

Figure 3. Smartphones and tablets have the potential to replace traditional handheld meters for portable measurements.

This idea of tethering a DAQ device to an off-the-shelf computing device is not a completely new concept for portable measurements. Previous attempts, such as miniature laptops, used conventional power-hungry processors and therefore provided unusable short battery life. Personal digital assistants (PDAs) offered longer battery life and were useful for some applications, but their underpowered processors limited their functionality.

These devices have evolved into today’s smartphones and tablets. They now pack more processing power than standard desktop PCs did 10 years ago and can be used to write more powerful processing routines for inline analysis directly on a device. The processors consume less power than standard PC processors so the devices are useful for longer periods of time. They include gigabytes of data storage, providing ample room to save logged data. Touch-screen technology offers an intuitive way of interacting with the user interface, which can be designed to mimic application-specific knobs, buttons, and controls. The features in mobile computing devices have evolved to create a viable platform for portable measurements that exceeds the capabilities of traditional methods.

Portable biomedical applications exemplify the need for this additional functionality. Emergency medical service (EMS) or first responders use portable tools to diagnose patients’ conditions. These devices must be small enough to deploy to ambulances and medical evacuation helicopters but powerful enough to perform the processing required for diagnostics and intelligent feedback. This is extremely important in time-critical markets with limited diagnostic resources, such as in military and emergency medical environments. Off-the-shelf computing technologies like smartphones and tablets help create more powerful, portable medical devices at lower costs.

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3. NI Tools for Mobile Devices

Building an application for a smartphone or tablet is not a trivial task. National Instruments has recognized that many of its customers have limited or no expertise programming for mobile platforms. To help engineers take advantage of these devices, NI has created several tools for remotely viewing measurements and connecting to data acquisition hardware.

Remotely View and Control Measurements with the Data Dashboard for LabVIEW app

With the Data Dashboard for LabVIEW app, engineers can create a custom, portable view of NI LabVIEW software applications. The app displays the values of network-published shared variables and/or Web services on charts, gauges, text indicators, and LEDs. Users can create custom layouts of one, two, four, or six indicators and quickly swipe between multiple layouts.

 

Figure 4. The Data Dashboard for LabVIEW displays the values of network-published shared variables and/or Web services.

To view an application from the Data Dashboard for LabVIEW, engineers must firsts create a desktop or embedded application that publishes data to the network. This can be done in one of two ways:

1. The simplest way is to add network-published shared variables to a LabVIEW VI. Using the shared variable,data is shared between loops on a single diagram or between VIs across the network. It is configured at edit time using property dialogs and no configuration code is required in the application.  

2. For more sensitive IT environments, engineers can add Web services to the application to invoke a method on a remote target using standard HTTP protocols. In this configuration, the Data Dashboard sends a request to the LabVIEW application, which processes the request and replies with a response. With the LabVIEW Web server, VIs can be deployed as Web services.

After the application is developed and Web services or shared variables are deployed, building a dashboard is as simple as browsing to the server and choosing the signals to monitor. Numeric, Boolean, or string data types can be monitored and each data type features multiple indicator types including LEDs and charts. The Data Dashboard Mobile for LabVIEW app has the same functionality, but only has one indicator per dashboard instead of the multiple indicator layout more easily readable on a tablet.

 

Figure 5. The Data Dashboard for LabVIEW features multiple indicator types including charts, gauges, LEDs, and labels.

With the Data Dashboard for LabVIEW app on the iPad, engineers can develop customized dashboards that can both monitor and control applications. With iPads making up the majority of industrial tablets used worldwide as of 2012, this functionality is first being brought to this platform with an eye on future hardware trends. With this new functionality, users can create complete free-form layouts for their dashboards, add custom background images and control/indicator color themes, connect securely to applications using secure LabVIEW web services, and sharing mechanisms for dashboards.

 

Figure 6. The Data Dashboard for LabVIEW app running on the iPad

Download the Data Dashboard for LabVIEW (iPad)

Download the Data Dashboard for LabVIEW (Android Phones and Tablets version 2.3 or higher)

Download the Data Dashboard for LabVIEW (Windows 8 devices)

Wireless NI CompactDAQ Support for Mobile Devices

NI Labs (decibel.ni.com/content/groups/ni-labs) showcases evolving technologies from National Instruments that aren’t quite ready for full release. Recently introduced in the labs is a firmware upgrade for wireless NI CompactDAQ chassis that adds support for mobile devices. Engineers can directly connect the NI cDAQ-9191 chassis to a smartphone or tablet via existing Wi-Fi infrastructure or an ad-hoc Wi-Fi network. 

Figure 6. Engineers can use a smartphone or tablet to wirelessly take voltage measurements from a cDAQ-9191 chassis.

There are two options for visualizing measurements from the cDAQ-9191 using a mobile device:

1. The simplest option is to download the cDAQ-9191 Data Display app for iOS or Android, which lets users easily configure, visualize, and share measurements. Pinching the graph zooms in on a signal and holding a point on the signal displays its value. Users can also email an image of the graph and data in a .CSV file.

2. The firmware upgrade also exposes a Web API that is used to program custom apps that connect to a cDAQ-9191. The API includes functions for configuring and running measurement tasks. Documentation and example code is also available for performing finite and continuous measurements and discovering networked devices.

Learn more about the firmware upgade on NI Labs

Collaborate on the NI Community

The NI community group for smartphones, tablets, and mobile devices is a great place to share ideas, download example code, give feedback on future NI products, and collaborate with other users who are incorporating mobile devices into their projects. NI has also published tutorials and example programs for building native Apple iOS and Google Android applications for connecting to LabVIEW Web services and graphing data. 

Join the NI Community for mobile devices

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4. Next Steps

Watch the webcast on Mobile DAQ With Smartphones and Tablets

Getting Started
Getting Started with the Data Dashboard for LabVIEW
NI cDAQ-9191 Mobile Device Support

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Customer Reviews
12 Reviews | Submit your review

 - Jan 31, 2013

Why android versions don´t have more functionalities? Very poor this app. In university maybe, this software is functional.

Bluetooth ? - Nov 8, 2012

In an industrial setting, the IT security load for ethernet/WIFI connections is high. But, a Bluetooth connection can provide a Local, physically secured connection for maintenance personnel needing to access equipment which might only be connected via wired ethernet. Display of variables when evaluating or diagnosing machine performance without the expense of a fulltime dedicated local HMI could mean a significant cost savings. The Tablet becomes a portable HMI connected through bluetooth. LabVIEW display over bluetooth on Android ? Hmmmm

Data dashboard is pretty pointless.. - May 1, 2012

I want something that works in BOTH directions - i.e. that lets me send control commands to my device as well as letting me monitor data. Additionally having to set up shared variable screens seems rather cumbersome and ad hoc after I tried it, it is not elegant.

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