Home Hard & Software What's New! Feedback Search References

 

Wireless Data Acquisition might reasonably be divided into two categories, low speed sensor networks for data logging/and limited digital IO, and higher speed sensors on networks that support high-speed data transfer.  I will limit my discussion here to wireless networks that support multiple devices.  There also will be a number of purpose-built systems that use point-to-point wireless connections.

High-speed networks, generally, use 802.11 b/g infrastructure, and support data acquisition rates of up to 50 K samples/s.  Wi-Fi range is variable, but generally less than 100 m, without repeaters or other range extenders, might be expected.  Also, power requirements will restrict such devices to AC power, or battery packs with fairly short lifetimes. 

Low-speed networks offer advantages over higher speed, and the two most obvious are reduced cost and power requirements.  The reduced power requirements make battery powered devices practical, with battery life of several years, in some cases.  Generally, such networks will employ ZigBee (see: http://www.zigbee.org/) architecture.

The November 2009 issue of Design World magazine published a useful article, titled "Are Wireless Sensor Networks really ready for industry?"  Click the link at the left to view this article.

The following are two offerings from National Instruments (I have seen these in action, so I have some familiarity with their use).

National Instruments Wi-Fi Data Acquisition

NI Wi-Fi Data Acquisition
 
bullet Use widespread IEEE 802.11 (Wi-Fi) infrastructure for remote measurements
bullet Stream data on each channel at more than 50 kS/s with up to 24 bits of resolution
bullet Simplify remote monitoring with LabVIEW and direct sensor connectivity
bullet Protect data with 128-bit AES encryption, the highest commercially available standard
bullet Seamlessly integrate wireless measurements into existing systems
 

NI Wi-Fi data acquisition (DAQ) devices combine IEEE 802.11 wireless or Ethernet communication; direct sensor connectivity; and the flexibility of NI LabVIEW software for remote monitoring and control of electrical, physical, mechanical, and acoustical signals. NI wireless DAQ devices can stream data on each channel at more than 50 kS/s with 24 bits of resolution. In addition, built-in NIST-approved 128-bit AES encryption and advanced network authentication methods offer the highest commercially available network security. With the flexibility of LabVIEW graphical programming and the ubiquity of 802.11 network infrastructure, Wi-Fi DAQ makes it easy to incorporate wireless connectivity into new or existing PC-based measurement or control systems.

NI wireless DAQ devices consist of an NI C Series measurement module and a Wi-Fi carrier. The NI WLS-9163 is a single module C Series carrier that provides both 802.11b/g and Ethernet connectivity back to a host PC, while the NI ENET-9163 is a single module carrier with only Ethernet connectivity. C Series modules provide direct sensor connections and built-in signal conditioning for a variety of measurements, including temperature, strain, acceleration, current, and voltage. You can use them interchangeably for a variety of measurement and control applications across several platforms, including NI CompactDAQ and CompactRIO, and an NI single module USB carrier. You may purchase WLS-9163 carriers and C Series modules separately or together as NI WLS-9xxx devices:

Analog Input Devices

WLS-9211 (4-channel, 14 S/s, 24-bit, 80 mV thermocouple input)
WLS-9213 (16-channel, 75 S/s, 24-bit, 80 mV thermocouple input)
WLS-9215 (4-channel, 100 kS/s/ch, 16-bit, 10 V analog input)
WLS-9219 (4-channel, 100 S/s/ch, 24-bit, 60 V, 25 mA universal input)
WLS-9234 (4-channel, 51.2 kS/s/ch, 24-bit, 5 V IEPE input)
WLS-9237 (4-channel, 50 kS/s/ch, 24-bit, 25 mV/V bridge and strain input)

Digital I/O Devices

WLS-9421 (8-channel, 11 to 30 VDC, 24 V logic, sinking digital input)
WLS-9472 (8-channel, 6 to 30 VDC, 24 V logic, sourcing digital output)
WLS-9481 (4-channel, 60 VDC, 250 Vrms, SPST electromechanical relay)

 

 

National Instruments Wireless Sensor Networks

The NI wireless sensor network (WSN) platform delivers battery-powered nodes that offer industrial certifications, reliable networking protocols, and optional outdoor enclosures for long-term, stand-alone deployments. You can take advantage of NI LabVIEW software integration with NI WSNs to select between Windows and LabVIEW Real-Time OSs and simplify the extraction of high-quality measurement data.

Learn more about wireless sensor networks
 
Product Image

View a 10-minute webcast covering WSN basics  View the webcast

Product Image

See how you can build an entire WSN system with NI LabVIEW  View the webcast

 

Send mail to dick_grier@hotmail.com with questions or comments about this web site.
Last modified: 11/25/09
Hit Counter