Websensor Description
Electronic sensors are one of the primary inputs to computers and electronic data networks. Where remote data acquisition is required, internet-accessible sensors are an obvious choice but convenient, compatible, low-cost sensors are not widely available. The websensor series are sensors with built-in signal conditioning and a mini-web address. Users are able to access the sensor directly or, more conveniently, via an Esensors website (eesensors.net) which stores and displays the data in a graphical form.
The main parts of the websensor consist of a base unit together with two communication ports (Ethernet and Esbus). The Esbus combines a networked version of the SPI serial bus and RS232. The Ethernet is the route to the Internet. Within the base unit are microcomputers which handle the Internet protocol, the communication ports, and, in some cases, the sensor and sensor signal conditioning. A websensor has no switches, keyboard or (required) display because it functions as a sensor, not as a computer. Additional sensors may be connected to the base unit by the Esbus (networked), RS232, or an IEEE1451 port, depending on the model. 
While the websensor itself is a small website, it has been designed with limited memory and capability in order to minimize cost and data transfer time. Its main function is to send sensor data in http format, upon request of a central website. The central website is similar to a standard website except that is programmed to request data at periodic intervals, and update its database on all sensors for which it is responsible. A user requiring the sensor data will access the central website for the information. It displays current and historical data in a graphical format.
References to Websensor Papers and Presentations
- D. Wobschall, "Websensor Design - Smart sensors with an Internet Address" Proceedings Sensors Expo (Philadelpia, Oct. 2001)
- Darold Wobschall and Hari Sai Prasad K. Esbus - "A sensor bus based on the SPI serial interface" presented at IEEE Sensors 2002 (Orlando, June 2002)
- Darold Wobschall , "An Implementation of IEEE 1451 NCAP for Internet Access of Serial Port-Based Sensors," SiCon02 ( Houston , Nov. 2002)
- Hari Sai Prasad K. and Darold Wobschall , "A Web enabled multi-port NCAP Interface" to be presented at ISA (June 2003)
- Darold Wobschall , "Ian IEEE 1451 NCAP Prototype with Multiple Serial Ports and Internet Access to be presented at Sensors Expo (June, 2003)
- D. Wobschall, "An IEEE 1451 NCAP Prototype ," Proc. Sensors Expo (June 2003) and D. Wobschall "IEEE 1451 Prototype Dot 2 and Dot 4 NCAPs with Internet Access", Proc. Sensors Expo (Sept 2003)
- D. Wobschall and W. S. Poh, " A Smart RTD Temperature Sensor with a Prototype IEEE 1451.2 Internet Interface" SIcon/04, New Orleans , January, 2004
Additional references on smart sensors and the IEEE 1451 standard
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