Diagnostics, Asset Management

Diagnostics, Asset Management February 1, 1998

What Isn’t an MES?

What isn't an MES? A recent manufacturing execution system (MES) model (one of eight) encompasses eleven broad functions, some not typically applied to MES software.There's something within the models to help everyone understand MES. Proponents suggest using a suitable model, selecting some MES software, and start realizing the benefits—an average 45% reduction in manufacturing cycl...

By Mark T. Hoske, Control Engineering
Diagnostics, Asset Management February 1, 1998

Is There a Shortage of Engineers?

Feel like there is not enough of you to go around? Maybe it's because there aren't enough engineers to do all the work.The U.S. Department of Commerce has released a study by the Information Technology Association of America (ITAA) showing a shortage of 70,000 computer scientists and systems analysts per year.

By Gary Mintchell, Control Engineering
Diagnostics, Asset Management January 1, 1998

Data Dispels Manufacturing Myths, Equipment Expansion Expected

With apologies to Mark Twain, reports of declines in U.S. manufacturing are greatly exaggerated.A recent study, The Facts About Modern Manufacturing, describes manufacturing's pivotal role in the U.S. economy and combats popular misconceptions. Compiled by the Manufacturing Institute, an affiliate of the National Association of Manufacturers (NAM, Washington, D.

By Staff
Diagnostics, Asset Management March 1, 1997

Control Valves: Sizing, Design, Characteristics

C ontrol valves are devices with movable, variable, and controlled internal elements for modulating fluid flow in a conduit. The valve restricts flow in response to the command signal from a process measurement control system. Basically, a control valve consists of a pressure containment enclosure body and various internal elements--fixed and movable--commonly called the valve trim. While there are uncommon exceptions, control valves are designed to function in either a push-pull or linear sliding-stem manner, or in a rotary-stem manner.

By Control Engineering Staff
Diagnostics, Asset Management February 1, 1997

Velocity Is Key to Motion Control

Motion control systems are generally designed to move a load along a specified path as fast as possible without damaging the load or the mechanism driving it. Heavy loads are particularly difficult to control since inertia tends to force the load off course during high acceleration maneuvers. Worse still, the stress of resisting the load's inertia can destroy not only the drive mechanism, but the load itself. Rotating machinery, linear conveyors, and multiaxis robotic arms all share these problems, but a more familiar example of heavy-load motion control is the passenger elevator.

By Vance J. VanDoren, consulting editor