60th Anniversary: CE History from 60, 30, and 15 years ago on automatic control patents, level sensing systems, data acquisition, and analog signals
Happy 60th, Control Engineering! Help us celebrate by looking at issues from 60, 30, and 15 years ago. Control Engineering magazine first published in September 1954. This monthly column in 2014 will review coverage in issues 60, 30, and 15 years ago. While technologies have progressed since then, topics below (automatic control patents, level sensing systems, data acquisition, and analog signals) remain relevant today.
November 1954: What's patentable in automatic control?
Essential to any industry are the patents that define the intellectual property on which it is founded. In the electronic industry, for example, a clear-cut starting point is the patents of such inventions as radio transmission and thermionic vacuum tubes.
Automatic control, on the other hand, is an outgrowth of existing industries. The industry may appear, at times, to be new more in magnitude than in kind. As any field matures, it gradually becomes more complex. But what sets automatic control apart as a new industry is that the increased complexity has come about at an accelerating rate through the past decade by combining instruments with production and handling machinery.
The nature of automatic control suggests an important characteristic of the patents that can be expected. Because many of the innovations will be aggregations of existing technologies and equipment, even some of the most spectacular developments may prove unpatentable as being simple combinations. The inventions that are made, however, will be highly complex.
November 1984: ICs deliver more control capabilities
Very-large-scale integration (VLSI) circuits provide a focal point for a new strength in the industrial process and manufacturing control market as well as the consumer market, much in the same way the automobile did over 50 years ago. These silicon chips have affected many aspects of our personal and work lives, and spawned new industries. But even with so many markets and business already reeling from their impact, new areas of influence are still being sought.
Automatic control has already experienced a great deal of change resulting from VLSI microprocessor products that have been developed for other consumer and communication applications. Now with a tremendous increase in capital spending for factory automation, the integrated circuit (IC) makers appear to have increased their endeavors to produce special products for control.
November 1999: One-chip data acquisition gives elbow room to analog signals
You can talk about digital fieldbus and wireless Ethernet. But there's nothing like good old analog signal over a 4-20 mA loop for transmitting data between process and control equipment-though engineers are using some unusual tools to help them create smaller and more powerful analog peripheral boards and boxes.
These peripherals are needed in process control applications to convert analog signals so they can be read by digital PLCs, process control systems, or industrial PCs. However, snowballing needs by users and applications for more channels per board and smaller packages are leading to shortages in board space power, which is fueling the search for more efficient peripherals.
- 2014 edits, to fit this page, by Chris Vavra, production editor, CFE Media.