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PLCs, PACs

PLCs, PACs September 1, 1996

Sampled Control, Better Results With Less Data

Control Engineering classic: In this article, the consequences of performing feedback control with sampled rather than continuous data are examined.

By Vance J. VanDoren, CONTROL ENGINEERING
PLCs, PACs May 1, 1996

The Smith Predictor: A Process Engineer’s Crystal Ball

Arguably the trickiest problem to overcome with a feedback controller is process deadtime -- the delay between the application of a control effort and its first effect on the process variable. During that interval, the process does not respond to the controller's activity at all, and any attempt to manipulate the process variable before the deadtime has elapsed inevitably fails. This classic article is among the most-read on the Control Engineering site. (See diagrams.)

By Vance J. VanDoren, CONTROL ENGEERING
PLCs, PACs January 1, 1970

Three web server architectures aid plant-floor, enterprise integration

Driven by manufacturing's desire to connect the factory floor with the rest of the enterprise, web-enabled PLCs and Ethernet are giving users new ways to view and control factory data using embedded web servers. When selecting a web-enabled automation device, users can choose from three distinct system architectures.

By Richard Baker
PLCs, PACs January 1, 1970

Innovations inundate National Industrial Automation Show at National Manufacturing Week 2001

Chicago, Ill.— Hundreds of exhibitors showed thousands of innovative products and services at the National Industrial Automation Show during National Manufacturing Week 2001 at McCormick Place. For more coverage, including streaming video clips, click on "NMW 2001" at www.controleng.com. Advantech Automation (Cincinnati, O.

By Staff
PLCs, PACs January 1, 1970

Schneider sues Opto 22

Chicago, Ill.—Wherever two or more gathered during National Manufacturing Week 2001, March 5-8, their discussion involved patents. As reported in Control Engineering, Feb. '01, p. 32, Schneider Electric Automation (North Andover, Mass.) followed news about its minority investment in Entivity by announcing an open auction on the web for its patent, "Device for Communicating Real-time Dat...

By Gary Mintchell, senior editor, gmintchell@cahners.com
PLCs, PACs January 1, 1970

Pressure Sensing: It’s Everywhere!

KEY WORDS Process control and instrumentation Process sensing Pressure sensing One of the most-used sensors, pressure instrumentation is found nearly everywhere now. The old process standby is still there—chemical change-of-state monitoring still requires tracking such mundane variables as pressure and temperature—but it now can be found, however tiny, in manufactured goods from au...

By Dick Johnson, CONTROL ENGINEERING
PLCs, PACs January 1, 1970

Components provide network, Internet capabilities

Alpharetta, Ga. —Simatic Net series of control hardware, firmware, and cabling options complements this line of high-speed switches that integrate production floor and critical IT data at 100 Mbps. These industrial Ethernet components allow users to build a high-bandwidth network with Internet management capabilities and are optimized for connectivity with a native-socket, TCP/IP firmwa...

By Staff
PLCs, PACs January 1, 1970

Ethernet Security, Safety Relies on Common Sense Networking

KEY WORDS Networks and communication Ethernet Internet and intranet PC-based control Device-level networksThe price of freedom? A little less freedom. More users are seeking to gain Ethernet's interoperability and flexibility. However, the relatively greater openness of Ethernet can mean increased network vulnerability, especially when networks are linked via the Internet.

By Jim Montague, CONTROL ENGINEERING
PLCs, PACs January 1, 1970

Applied Data to use Synergetic chip in computer

Applied Data Systems (Columbia, Md.) and Synergetic Micro Systems (Downers Grove, Ill.) announced March 5 at NMW a collaborative design effort to produce a new 32-bit StrongARM computer incorporating Synergetic's EmbeddedComm/EC-1 universal fieldbus chip. The two partners report their new product suite will be sold to OEMs and equipment suppliers, and expect the suite to offer price and perform...

By Staff
PLCs, PACs January 1, 1970

Securing software

Chicago, Ill.—Software security is based on how applications and operating systems are constructed, but security also involves plant procedures, building security, and employee education, among other things, according to key software vendors at National Manufacturing Week, March 3-5, here. Proper software security measures are "very scarcely implemented," according to Dirk Rouffaer, Schne...

By Mark T. Hoske, editor-in-chief, mhoske@cahners.com