Top 5 Control Engineering articles, September 15-21: Salt used as renewable energy, The first PLC, future of the PLC, more

Articles about salt being used as an energy resource, the competition for the first PLC, the PLC’s future, cascade control fundamentals, and writing a process operation document were Control Engineering’s five most clicked articles from last week, September 15-21. Were you out last week? Miss something? You can catch up here.

By Chris Vavra September 22, 2014

Control Engineering Top 5 most read articles online, for Sept. 15-21, covered using salt as an energy source, the competition for the first PLC, the future of PLCs, cascade control fundamentals, and a tutorial about how to write a process operations document. Link to each article below.

1. The power of salt for renewable energy

MIT study investigates power generation from the meeting of river water and seawater. 

2. Inside the competition for the first PLC

The race to develop the first programmable logic controllers was underway inside General Motors’ Hydra-Matic Transmission Division in Ypsilanti, Michigan, in 1970. Three finalists had very different architectures.

3. Future of the PLC

PLCs are evolving and continue to be the best option for a variety of industrial automation applications. Greater programming flexibility and ease, scalability, more memory, smaller sizes, very high-speed (Gigabit) Ethernet, and built-in wireless are among evolving programmable logic controller features. 

4. Fundamentals of cascade control

Sometimes two controllers can do a better job of keeping one process variable where you want it.

5. How to write a good process operation description document

Back to Basics: Describe your process to preserve the process engineer knowledge for the future. To program the process controller, programmable logic controller (PLC), or distributed control system (DCS), follow these steps and methodology.

The list was developed using CFE Media’s web analytics for stories viewed on, September 15-21, for articles published within the last two months.

– Chris Vavra, content specialist, CFE Media,