Michael Drakulich, assistant editor
Control engineers need more than to be told what's going on. They can't take anyone's "word for it." They need to see things for themselves. They need visual reassurance their processes are moving along according to plan, whether that means they're looking at the actual process, or monitoring it with a visual aid.
If control software can be compared to human nerve impulses, then wire and cables are the nerve fibers they travel over. Wire and cable for networking and communication is responsible for taking data from field devices and transporting it to a processing device, such as a PC or PLC. The PC or PLC (brain) can then decide how it will act.
Check the Monday-morning newspaper in the fall for pro football, and you'll see plenty of praise for the running back that gains over 100 yards and scores two or three touchdowns. You may even read how a quarterback "had all day to throw the football," amassing gaudy statistics that make fantasy football leaguers delirious.
One of the best ways to conceptualize data acquisition software is to compare it to the human body's nervous system. Acquiring data is similar to the body's signaling process when it encounters stimuli. When a person goes from an air-conditioned room to 907 F heat and 80% humidity outdoors, nerve endings all over the body send electric impulses to the brain saying, "Hey, it's hot and mugg...
Control Engineering product research shows discrete sensors are getting smaller and easier to setup, and they can include short-circuit protection. Sensors need to detect transparent objects, differentiate between the object and background, detect flaws in microcomponents, automatically adjust to changing conditions. See charts.
The most functional, easiest to use, and most innovative control equipment is useless unless it's sheathed in a protective cover. Protection of this sensitive, often fragile equipment may be just as vital to the control engineer as the function they are designed to perform. Now, control equipment is performing in more and more harsh environments, and beside the contaminants they encounter...
An old proverb states a little body often harbors a great soul. The same may be said for the tiny, and oft overlooked terminal block. But, "Like any other control, in order to save money, users need to reduce panel and enclosure sizes, especially if they're custom made," says John Nussbaum, staff marketing engineer for Square D (Palatine, Ill.