While wireless sensor networks have been a hot topic for years, the technology is just beginning to leave the laboratory and appear in real-life implementations in the industrial sector. The software provided by today's wireless sensor vendors includes the basics for performing wireless measurements—node configuration and management, as well as data logging and display. But to move to broader acceptance of the technology, the next generation of software must deliver three high-level features: node intelligence and automation, node aggregation, and integration with the rest of the enterprise (Figure 1).
Figure 1. As the number of real-life wireless sensor network implementations in the industrial sector grows, it becomes apparent that the next generation of software must provide intuitive, easy-to-use tools to create node intelligence and automation
Nearly every wireless sensor vendor's software provides some level of node configuration. For example, a user can add a node to the system, manually put it to sleep or wake it up, and configure how fast it streams data. Some software packages also visually represent where the node is located on a floor plan of the facility. And most software also offers information on the state of each node, indicating whether the node is connected to the network and actively transmitting data.
Nearly all software packages display real-time wireless sensor data on a graph for monitoring purposes. And some provide an interface that allows you to set up basic data logging, making it possible to export data to a spreadsheet for offline analysis (Figure 2).
Figure 2. Currently, most wireless sensor node data can only be logged to a spreadsheet. No easy automated method exists for distributing the data throughout the enterprise
While these software tools are fairly intuitive, they typically have fixed capabilities and lack several features that many users view as necessary for wireless sensor networks to be truly useful.
Today, most wireless sensors are passive nodes that simply pass back the data they are hard-coded to provide. Few have built-in intelligence for data analysis or automated power management. The nodes that do have a way to incorporate additional intelligence use programming interfaces that are not nearly as simple as the node management interface described earlier, and often you must resort to low-level text-based programming. This is a less than ideal situation for engineers and scientists who may be experts in their fields but who are not embedded programmers.
To make wireless sensor technology more palatable for a broader segment of the market, software for programming and managing sensor nodes must provide greater functionality.
Node Intelligence and Automation. Next-generation software must offer intuitive, easy-to-use tools to customize hardware nodes with additional intelligence, such as local analysis. Local analysis facilitates scenarios in which higher-power gateway nodes aggregate and process data from several lower-power nodes and pass minimal information, such as the result of a limit test, back to a central location.
New software must also make it possible to quickly acquire data (e.g., several Ksamples/s) and store it locally, passing back only parametric data. For example, a node might be embedded in a large machine to monitor vibration levels. Although it can acquire a large amount of raw data, it may need to send only pass/fail information to the host, indicating whether the machine is within acceptable limits.
Node Aggregation. Current node management software works well for networks of 20–30 nodes, but when an organization wants to implement a network consisting of hundreds or thousands of nodes, the setup becomes time-consuming. It is difficult to program each node individually. Unfortunately, current wireless sensor technology cannot easily scale beyond research and small applications.
The next generation of software for programming and configuring nodes must be able to aggregate them into groups and program an entire group at a time with the same function. For instance, an oil company may want to monitor the flow in their pipeline at many points. Because all nodes will perform the same task—monitor flow and log or pass data back to a central location—the company can save time and money if they can program all nodes at once. Node aggregation will make it possible to create a simple, easy-to-use interface for developing redundant systems and consequently will speed the configuration of large networks.
Integration with the Enterprise. Before fully adopting wireless sensor technologies beyond niche applications, most companies will demand the ability to easily integrate their sensor networks with the rest of the enterprise. This means providing not just a method for data logging and offline analysis but also a way of passing data directly among a hybrid network of wireless sensors and business systems that use different networking protocols. This, in turn, requires online analysis capabilities. Being able to aggregate data and provide access via a Web server is an optional but often important feature for companies whose employees are spread across the globe or who want to give multiple internal consumers easy access to the data.
As wireless sensor networks continue to grow and hardware platforms and protocols proliferate, the software must scale to meet the growing needs of users who can most benefit from implementing them.
A Potential Solution
Although it does not yet have the capability to program multiple nodes simultaneously, LabVIEW, National Instruments' graphical development environment, offers a way to program nodes, add intelligence, and integrate wireless sensor data with the rest of the enterprise (Figure 3).
Figure 3. LabVIEW provides database connectivity and a built-in Web server that lets you easily integrate wireless sensor node data with the rest of the enterprise
Node Intelligence and Automation. With the recently released LabVIEW Embedded Development Module, you can program any 32-bit processor and, therefore, any wireless sensor based on a 32-bit processor. Using this tool, wireless sensor vendors can develop drivers for their wireless nodes so that end users can program the nodes with LabVIEW. As a result, wireless sensor users can add custom intelligence to their nodes without complex register-level or text-based programming.
Integration with the Enterprise. LabVIEW and its toolkits offer compatibility with many networking protocols, such as TCP/IP and Bluetooth, and databases, such as Microsoft Access, SQL Server, and Oracle. As a result, a host computer can run a LabVIEW program to aggregate data from multiple wireless sensor nodes and automatically send it to other machines on the network or store it to a database. In addition, LabVIEW Full Development Systems and higher include a built-in Web server, so a host computer can aggregate data from the nodes and provide the data in real-time to a Web site that clients can access and even control through their Web browser. Even though LabVIEW cannot yet program multiple nodes at once, a user can build a standard configuration, save it, and download it to each node in turn.
By providing LabVIEW drivers for wireless sensors, manufacturers can open the door to a whole new set of users who require easy-to-implement node intelligence and integration with the rest of their enterprise.