Internet-based SCADA systems

Internet-based SCADA systems

The Internet has now been dedicating a new and highly-efficient medium for sharing information all over the world. The development of web technologies allows information to be displayed numerically and graphically on any conventional Internet browser. Via Internet browsers (or web-browsers), end users can access, monitor the real-time data and even control the field devices and equipments.

Supervisory Control and Data Acquisition (SCADA) systems are now becoming more and more popular in industrial processes and the demands in functionality and high performance have been increasing rapidly. Furthermore, the fast development of microprocessor manufacturing and Internet technology makes it more efficient and cost-saving to design such systems with the embedded network protocol modules.

Overall block diagram

A best solution on implementing Internet-based SCADA systems is with the presence of embedded TCP/IP Protocol stacks. The solution provides the following features:
• Automatically collect the latest system’s data and real-time data are displayed on web-browser interfaces.
• Users can manage and issue command controls on system’s devices from any internet-connected place.
• Security issue is carefully considered with: server protection by router; user authentication & IP approval on server application software and MD5 algorithm for data encoding. This helps reduce the threat of the public nature of the Internet.
• New sites/devices can be added/deleted/tracked.
• System operation can be tracked for each user by the event log tool.
These type of decentralised control can be more efficient and fast compared with conventional methods.

VIRTUAL INSTRUMENTS BEYOND THE PERSONAL COMPUTER

VIRTUAL INSTRUMENTS BEYOND THE PERSONAL COMPUTER
• Recently, commercial PC technologies have begun migrating into embedded systems. Examples include Windows CE, Intel x86-based processors, PCI and CompactPCI buses, and Ethernet for embedded development. Because virtual instrumentation relies so heavily on commercial technologies for cost and performance advantages, it also has expanded to encompass more embedded and real-time capabilities.

• For example, LabVIEW runs on Linux as well as the embedded ETS real-time operating system from VenturCom on specific embedded targets.

• The option of using virtual instrumentation as a scalable framework that extends from the desktop to embedded devices should be considered a tool in the complete toolbox of an embedded systems developer.

• A dramatic technology change example that affects embedded systems development is networking and the Web. With the ubiquity of PCs, Ethernet now dominates as the standard network infrastructure for companies worldwide.

• In addition, the popularity of the Web interface in the PC world has overflowed into the development of cell phones, PDAs, and now industrial data acquisition and control systems.

• Embedded systems at one time meant stand-alone operation, or at most interfacing at a low level with a real-time bus to peripheral components.

• Now, the increased demand for information at all levels of the enterprise (and in consumer products) requires you to network embedded systems while continuing to guarantee reliable and often real-time operation.

• Because virtual instrumentation software can combine one development environment for both desktop and real-time systems using cross-platform compiled technology, you can capitalize on the built-in Web servers and easy-to-use networking functionality of desktop software and target it to real-time and embedded systems.

• For example, you could use LabVIEW to simply configure a built-in Web server to export an application interface to defined secure machines on the network on Windows, and then download that application to run on a headless embedded system that can fit in the user's hand.

• This procedure happens with no additional programming required on the embedded system. You then can deploy that embedded system, power it, connect to the application from a remote secure machine via Ethernet, and interface to it using a standard Web browser.

For more sophisticated networking applications, you can graphically program TCP/IP or other methods with which you are already familiar in LabVIEW and then run them in the embedded system.