Web Demo Shows Live Data in a PDA or Cell Phone



The latest web demo (http://www.opcdatahub.com/Features/OPC_to_Web_MobileDemo.html) of the OPC DataHub (http://www.opcdatahub.com) from Cogent Real-Time Systems lets anyone using a PDA or cell phone interact with a live system--to view data in real time, and to send commands for controlling the system. Three increasingly sophisticated technologies: ASP, polling AJAX, and streaming AJAX, are employed to take full advantage of the wide range of devices on the market today.

This demo is as simple as typing a URL into your mobile web browser, said Andrew Thomas, President of Cogent. If your device supports AJAX, you should see live data in the display. Otherwise, with ASP you will capture the most recent data. Either way, you can enter new values into your mobile device and verify the results from your desktop web browser.

The mobile web display (http://www.opcdatahub.com/Features/OPC_to_Web_MobileDemo.html) is powered by OPC DataHub software running on a Cogent server attached to the Internet. Other web pages on the server show the same simulation data in a variety of ASP, AJAX and Java displays. When a user connects to one of these web pages, they establish a client connection to the OPC DataHub software. If a user then enters a new value through the web display, the OPC DataHub immediately sends this new information to all other registered client connections. Thus all participants can view each others's updates in real time.

Many of today'ss new mobile web browsers will support both the AJAX and ASP web displays, said Mr. Thomas. We have found the Opera Mobile Web Browser to be a good alternative if users experience any problems with the browser that comes with their device.

In this do-it-yourself demonstration Cogent showcases three web technologies to cater to different users. Streaming AJAX gives very fast updates for large numbers of people, using minimal system resources and bandwidth. Polling AJAX offers fast, economical connectivity for a moderate number of users, but requires more resources. Both of these require that the cell phone or PDA be AJAX-enabled.

The alternative is ASP, which most modern cell phones support. The ASP page provides a snapshot of the most recent data, which can be updated manually at any time. It has very low system and bandwidth requirements, and is ideal for displaying slow-changing data, such as is used in shift reports or statistics.

The OPC DataHub gives quick, reliable, and secure access to valuable information direct from the factory floor. It is an integrated tool that can present live process data directly on an engineer'ss or manager'ss desk in a form most suitable: database, spreadsheet, or web page. It provides OPC tunnelling, bridging, and aggregation, and has a free API to support virtually any type of OPC connectivity required.

Founded in 1995, Cogent Real-Time Systems is the leader in real-time cross-platform data integration between Windows, Linux and QNX. Customers include the Bank of Canada, Cadbury Chocolate and the European Space Agency. Cogent leverages its experience in real-time data communications to provide the next generation of OPC products.





Web Demo Shows Live Data in a PDA or Cell Phone