06-30-2010 11:02 AM
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.
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.
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.
#
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.
#
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.
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.
#
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