OPC DataHub Uses Streaming AJAX and New Java Applets to
Create Dynamic Web Pages
The latest release of the OPC DataHub offers new web
technologies including streaming AJAX for dynamic data in a
web browser, and new Java applets for displaying real-time
data updates in gauges and trend displays.
Georgetown, Ontario (January 30, 2006)
The OPC DataHub from Cogent Real-Time
Systems now provides even more ways to visualize and interact
with real-time data in a web browser. Its new streaming AJAX
Web Data Browser displays immediate updates to data from a
wide range of sources like databases, spreadsheets, and OPC
servers. This streaming AJAX technology can be used in
conjunction with new Java applets for live displays of gauges,
trending graphs, progress bars and other animated
"These new technologies are ideal for visualizing
real-time data on the web," said Andrew Thomas, President of
Cogent Real-Time Systems. "Streaming AJAX reduces latency to
near zero, while using minimal bandwidth and system resources.
The new Java applets make it easier than ever to see your system
status at a single glance."
of web technologies that allow a web server to send and receive
data without having to refresh the page in the browser.
Streaming AJAX delivers the data asynchronously to the page,
following the "publish/subscribe" model of data connectivity.
No polling is required, which means no latency--the data is
updated on the page as soon as it changes at the source.
The OPC DataHub Java applets provide a way to animate a
web page using real-time data. They connect directly to the OPC
DataHub, and display the incoming data stream as a moving needle
in a gauge, a dynamically drawn line in a trend graph, an
expanding progress bar, or as numbers updating in a table or
"The streaming AJAX and Java applet technologies are
fundamentally different," said Mr. Thomas, "but they can be used
together. They complement the other OPC DataHub web
technologies: HTML, XML, ASP, and polling AJAX. This wide range
of choice lets you create efficient and visually appealing web
page displays of real-time data with very little effort."
OPC is the leading protocol for data communications
between industrial hardware devices and Windows software. The
OPC DataHub is a memory-resident real-time middleware
application that collects data from OPC servers and other
sources, and redistributes it to any number of clients, such as
Excel, ODBC databases, and web browsers. Now, with streaming
AJAX and updated Java applets, the OPC DataHub gives
unprecedented web-based data visualization capabilities to
real-time systems of any size.
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.