Globally Distributed Measurements in the Palm of Your Hand

[AMasters]

Envision a day when everything from bridges and buildings to  household appliances contain millions of sensors that are continuously  reporting usage and system health data over the Web.

For more than 20 years, NI LabVIEW has helped engineers and scientists incorporate the latest cutting-edge  technologies into their projects with an intuitive graphical  programming approach. The evolution began with virtual instrumentation,  using software to automate the control of box instruments. Advancements  in graphical programming have led to capabilities such as creating  custom hardware on field-programmable  gate arrays (FPGAs) and accessing the full potential of multicore  processors with inherent parallel execution and real-time  virtualization. Today, NI is pushing the boundaries of LabVIEW, so  developers can acquire, analyze, and present data on a global scale.

Installing Sensors Anywhere

The ability to distribute intelligent, low-power wireless sensors  over great distances for long-term deployment exists today. Wireless sensor network (WSN) platforms offer measurement hardware that is capable of running on  standard battery technology for up to three years. These sensors form  wireless mesh networks by relaying data back to a central gateway that  aggregates the data and provides connectivity to the wired world. With  these systems, engineers can take measurements in locations never  previously possible or economically feasible.

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Figure 1. LabVIEW and the NI WSN  platform make it easy to add battery-powered wireless measurements to  existing NI systems.

Every LabVIEW programmer has this technology in his or her toolbox  through native support for NI WSN hardware and drivers for a variety of  third-party WSN platforms. The NI WSN platform offers the flexibility to  choose a PC-based host controller or an embedded real-time controller,  such as NI CompactRIO, for  each WSN system, helping engineers create deployed solutions that  incorporate the advantages of wired and wireless measurements. Using the  LabVIEW  WSN Module Pioneer, it is also possible to create and wirelessly  deploy applications that run directly on NI WSN nodes. The resulting  application running on the node can perform embedded decision making;  extend battery life; and add custom analysis, such as interfacing, to  sensors.

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Accessing Data Anywhere with Web-Enabled  Hardware

All the data in the world is meaningless unless it can be collected,  analyzed, and accessed for informed decision making. The NI 9792  programmable WSN gateway is an embedded controller that acts as a data  aggregator for NI WSN measurement nodes and is programmable with the LabVIEW  Real-Time Module for creating systems that perform logging,  alarming, and analysis on acquired data, even in the absence of a PC.

Support for LabVIEW Web services on the NI 9792 gateway provides connectivity to any Web-enabled device, ranging from  IT-grade server machines to smartphones, so users can build systems with  globally accessible data.

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Creating a Proof of Concept – Monitoring the  NI Pond

To demonstrate the concept of globally accessible distributed  measurements, NI engineers built a WSN system to monitor a pond at the  NI headquarters in Austin, Texas, as shown in Figure 2. The NI  facilities team manages an extended detention storm water pond that  protects the local water basin from road and parking runoff. To function  properly, a minimum water level and pH must be maintained in the pond.  Before National Instruments introduced its WSN technology, installing a  wired system to automate measurements at the pond would have required  running wires under the entrance of the NI headquarters, which would  have disrupted thousands of employees and been cost prohibitive. The  ability to connect to measurements wirelessly helped avoid running power  and communication cables. Using LabVIEW and the NI WSN platform,  members of the facilities team began cost-effectively monitoring the  pond from their desks and could now log and trend data over time.

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Figure 2. Engineers at National  Instruments used LabVIEW and NI WSN measurement nodes to monitor the  conditions of a pond on campus, an application that was not economically  feasible with a wired measurement platform.

In this pond monitoring application, LabVIEW WSN code running on the  measurement nodes manages sensor power to conserve battery life,  performs embedded analysis to convert the raw sensor voltages to pH  value, and averages the water level readings to minimize noise from  disturbance and reduce the amount of data transferred. The measurement  data is sent wirelessly to the WSN gateway on the roof of the Truchard  Design Center R&D building, which is more than 200 m away. Using  standard Web services in the LabVIEW Real-Time Module, the data is sent  to a server on the internal network supported by the IT department. The  server archives the data and makes it publicly available on the Web.

With this system, any Web-enabled device or application can access  the data acquired at the NI pond. National Instruments is also investing  in new tools for developing browser-based, thin-client applications  that act as interfaces to distributed measurement systems.

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Prototyping on an Apple iPhone

Figure 3. Using standard Web services,  LabVIEW can serve up data to any Web-enabled device.

To take the idea one step further, an NI engineer used the iPhone  software development kit to build an application that communicates to a  Web service hosted on an NI 9792 WSN gateway, so he could view current  measurement values and node health information from anywhere on the NI  campus. LabVIEW does not run on the phone, but engineers use it to embed  intelligence on the NI WSN measurement nodes, acquire and analyze data  on the real-time gateway, and serve it up via a standard Web service.

– Kurt Williams