Hank Hogan, for Control Engineering
Articles
I/O Devices
Given that I/O devices tie together all elements of a control network, primary buying considerations are pretty basic: Does the I/O equipment support the fieldbus protocols and signal types needed? That sounds simple, but there's a dizzying array of possible protocols and signals to consider. There's also the question of I/O intelligence to bear in mind, as well as a number of other factors, su...
Programmable Logic Controllers
When buying a programmable logic controller (PLC), it's best to use TLC—technology and language considerations. Because a PLC is a type of computer, one factor in any budget should be the cost of developing an application on the chosen PLC—an expenditure that typically arises after the hardware is purchased.
Photoelectric Sensors – 2005-08-15
Photoelectric sensors are typically available in at least nine or more sensing modes, use two light sources, are encapsulated in three categories of package sizes, offer five or more sensing ranges, and can be purchased in various combinations of mounting styles, outputs, and operating voltages. It creates a bewildering array of sensor possibilities and a catalog full of options.