01 August 2003
Top technologies and events
Technology and change. Those are two words that seem to work very well together and fit within the boundaries of automation and control.
So, in this 50th anniversary year, InTech's editors, along with the 80 or so instrumentation and control experts throughout the industry, named the top technical developments or events that influenced the world of measurement and control.
James Watt, 1774
WORLD WAR II
U.S. process industries, particularly the chemical industry, played a major role in winning World War II. Competing chemical and equipment suppliers joined forces to respond to the national emergency. Four projects, in particular, were of unprecedented scope, including The Manhattan Project (1942), which produced the atomic bomb, high-octane aviation gasoline, synthetic rubber, and manufacturing penicillin. Demand for aviation fuel soared. Refineries expanded. In 1940 the average production was 30,000 barrels per day. By war's end, in 1945, it was 580,000 barrels per day.
In the late 1930s, Taylor Instruments researchers, for the first time, integrated previously separate proportional, integral, and derivative (PID) (then known as "pre-act") control into the Taylor Model 56R Fulscope controller. However, tuning was a problem. To solve it, Taylor engineers John Ziegler and Nathaniel Nichols developed the well-known "Ziegler-Nichols" method of tuning, still in use today. The procedure involves increasing the proportional response until one obtains a sustained oscillation (also referred to as "ultimate sensitivity"), setting the proportional adjustment to half the value that caused the ultimate sensitivity, setting the integral rate equal to the ultimate frequency, and setting the derivative or pre-act to one-eighth this frequency.
In 1928, Foxboro's first pneumatic operational amplifier laid the groundwork for an entire generation of pneumatic instrumentation, much of it still recording industrial processes in plants around the world. A year later, Foxboro followed with the first proportional-plus-reset (integral) controller.
Honeywell in 1938 introduced the first electronic potentiometer, Class 15, which implemented servo drive indicators and recording pens. In June 1944, Foxboro introduced the first all-electronic instrument line, the Dynalog temperature and pH recorders and controllers. What's believed to be the first electronic controller, the AutroniC, developed by Swartwout Co. of Cleveland, hit the market in 1951.
Brown Instruments (later Honeywell) in 1941 introduced the Model 15 chart re-corder. The instrument saw heavy use during WWII in the Manhattan Project and, after the war, by the chemical, petroleum, nuclear reactor, and power industries.
TRANSISTORS, INTEGRATED CIRCUITS
Everything in industrial and everyday life changed after John Bardeen, Walter Brittain, and William Shockley of Bell Laboratories invented the transistor in 1947. Products in the 1950s began moving from vacuum tubes to transistors, dramatically reducing power consumption, size, and costs, and significantly improving reliability. In the early 1970s, Intel's 4004 launched the "computer on a chip," single-chip microprocessor revolution.
BIRTH OF ISA
Model 15 chart recorder
Brown (Honeywell), 1941
Representatives from regional technical societies gathered in New York on 2 December 1944. At a second meeting on 17 February 1945 in Chicago, they adopted the name Instrument Society of America. ISA was officially founded at the third organization meeting on 28 April 1945, held in Pittsburgh, with 15 local instrument societies and about 1,000 members. The first issue of the ISA Journal, predecessor to InTech, was published 50 years ago, in January 1954.
PNEUMATIC DIFFERENTIAL PRESSURE TRANSMITTER
Introduced by Foxboro in 1948, in conjunction with appropriate "primary devices" (orifice plates, venturi tubes, etc.), Foxboro's "dP Cell" differential pressure (dP) transmitter provided the first relatively "bulletproof" method of measuring flow and level in process control applications. The dP Cell provided a means to accurately and reliably measure low-range differential pressures at pipeline static pressures, which could typically be hundreds of pounds per square inch, while providing protection against accidental overranges.
Engineers applied feedforward control to heat transfer and distillation in the 1960s, helped by the development of pneumatic and electronic analog multipliers.
BIRTH OF DISTRIBUTED CONTROL SYSTEMS
Pneumatic control panel
About the same time in the mid-1970s, Honeywell in the U.S. and Yokogawa in Japan introduced the first distributed control systems (DCS)—marking a significant and far-reaching change in the way one could configure and apply control systems. A four-person Honeywell group spent nearly two years synthesizing what a next-generation control system would look like. The project eventually led to the TDC 2000, a DCS that took Honeywell's industrial automation and control business from $5 million to $500 million in five years. The concept behind the Yokogawa Centum and Honeywell TDC 2000 was that supervisory minicomputers can control several microprocessor-based loop controllers with a push button and cathode ray tube (CRT)-based display for the operator rather than an annunciator panel.
FIRST PROGRAMMABLE LOGIC CONTROLLERS
Shipment of the first programmable logic controllers (PLCs), including the Modicon 084 designed in 1969 by Dick Morley, was a major milestone in the automation industry. Morley was first with graphical ladder logic as a programming language. Odo Struger is the father of Allen-Bradley's PLC and is credited with creating the PLC acronym. Other PLC inventors include Ray Golden of Information Instruments Inc. (III).
ROSEMOUNT DIFFERENTIAL PRESSURE TRANSMITTER
Distributed control system (DCS)
Rosemount's all solid-state differential pressure transmitter, introduced in 1969, changed the course of electronic transmitters. It still enjoys market leadership.
CONVERSION TO DIGITAL TECHNOLOGY
The first computer system applied to process control may be the DIGITAC machine developed in 1954 by Hughes Aircraft Co., which generated the first major patent in that field. In 1956, the first report appeared on results achieved by Donald P. Eckmann and his associates at the Case Institute of Technology regarding work on computer control of a batch hydrogenation process. In the late 1960s, Ted Williams of Monsanto Co. pioneered the use of computers in process control. Microprocessors hit process control in the early 1970s. "Affordable computer capability finally gave automation its name and provided real tools for practitioners in the field. Compared to that, everything else pales to a dull gray," said Lynn Craig.
Sensors on the moon
USDATA in 1978 introduced REACT, the industry's first user-configurable colorgraphic workstation (hardware and software), providing a human-machine interface (HMI) for programmable controllers. It followed in 1986 with PC-based FactoryLink, providing HMI and supervisory control and data acquisition (SCADA) functions. Genesis, by Iconics, also came in the 1980s. Microsoft Windows won the HMI/SCADA wars, however, led by Wonderware's InTouch.
IBM's PC, unveiled in August 1981, marked the beginning of the end for proprietary process control computers. That's because it also marked the beginning of Microsoft's arrival as a big time software and plant-floor player. The PC became the default original equipment manufacturer platform for a wide variety of instrumentation and control products. Microsoft's Windows software became the de facto standard on which hundreds of software and hardware systems built open systems—"open," providing they are Windows-based, Java-savvy, or Linux.
Desktop technology to plant floor
Wonderware, Intellution, Iconics, and others, 1990
With the possible exception of computing itself, it is hard to imagine another technology (or, more properly, collection of technologies) that has more potential to alter process control technology than does the Internet. Not only are Internet technologies and tools being applied in myriad ways to facilitate automation, but they also are being used to interconnect automation professionals in ways unimagined fifteen years ago.
ISA S50 standardized 4–20 mA analog signaling in 1982. Digital transmitters introduced in the mid-1980s by Honeywell and Rosemount led to the open Highway Addressable Remote Transducer (HART) standard, which also worked on standard analog wiring. HART today continues to be a popular way to connect field instruments to control systems. Since the late 1980s, competing vendors have pushed nearly 30 different bus technologies as industrial field or device buses. The twelve-year "bus wars" ending in 1999 marked a decade of chaos for the ISA SP-50 standardization effort, which culminated in 1999 with the International Electrotechnical Commission (IEC) Commit-tee of Action forcing a multiprotocol standard that wags still call the "eight-headed monster." Today, major protocols include Foundation fieldbus, HART, ControlNet, Profibus, DeviceNet, Modbus, Interbus, and AS-i. A recent survey, meanwhile, showed that more than one in five engineers use Ethernet or wireless Ethernet for either a majority or a portion of their measurements. Industrialized Ethernet flavors include Modbus/TCP, EtherNet/IP, ProfiNet, and Foundation fieldbus High-speed Ethernet.
GLOBAL AND ISA STANDARDS
Moore Products (Siemens), 1992
Three years after its formation, ISA published its first standard on thermocouples (temperature measuring devices) in 1948. ANSI/ISA-50.1-1982 (4–20 mA analog signaling), officially known as Compatibility of Analog Signals for Electronic Industrial Process Instruments, is one of the most widely used standards in industrial automation. Among other notable standards efforts: SP5.1, Instrumentation Symbols and Identification, which enables anyone with limited measurement and control knowledge to read a flow diagram; S7, the original 3–15 pounds-per-square-inch air pressure standard; IEC 61158 international Fieldbus standards; ISA 50.01 Fieldbus; ISA-SP84, Programmable Electronic System for Use in Safety Applications; and SP88, Batch Control Systems, which also sired SP95, the Enterprise/Control Integration Committee. Each of these events was disruptive technology that changed the industry. What is the next disruptive technology? Wireless perhaps by 2006?
THE SMITH PREDICTOR
Developed by Otto J.M. Smith, a professor at the University of California-Berkeley, the Smith predictor essentially works to control the modified feedback variable (the predicted process variable with disturbances included) rather than the actual process variable. The Smith Predictor was a precursor to model-predictive controllers and PID-dead time controllers.
EMBEDDED ADVANCED CONTROL
Embedded multivariable predictive control (MPC), used to provide basic and advanced regulatory control, first saw light in 1999 with Foxboro's I/A Series process controllers. With Emerson's DeltaV control system in 2000, embedded MPC changed the tool kit available to the typical control engineer for the first time in forty years. MPC function blocks replaced many of the control techniques previously used to address multivariable process control problems.