发表于:2003-06-26 15:16:00
13楼
提供一点背景资料,是英文.
In the 1970s, microprocessors began finding their way into new automation devices. The basic unit of automated systems is the individual automation device. Early devices were usually limited to a single function. Soon it became possible to buy a single loop controller that had selectable functions such as alarm switches, programmable ranges, auto-manual transfer, and multiple input/outputs. As computers gained acceptance they were increasingly employed in control applications with the input or output device(s), (I/O) connected directly to the computer.
As technology and experience progressed, the concept of a distributed control system (DCS) developed. In 1975, Honeywell introduced the TDC2000, which used racks of printed circuit boards and performed the control functions for more than one loop. The operator interface was via monitor and keyboard. Competitors soon followed with their own versions. The term DCS was born under the concept of distributing processing power of a single processor to multiple devices. Later, the term came to mean distributed microprocessors—that is, the distribution of the processors themselves to locations throughout a facility.
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Timeline based on IEEE Annals of the History of Computing, Vol. 17, No 1, 1995, “Pioneering Work in
the field of Computer Process Control”, T.M. Stout and T.J. Williams
Late 1940’s Commercially available computers
Mid 1950’s Two paradigms identified: “supervisory control” and “direct digital control”
… Ramo-Wooldridge Company (later TRW) actively seeks partners to produce
a viable system – RW300
Sep. 1958 First industrial computer system; plant monitoring for power station
Mar. 1959 First industrial control computer system; closed loop control of catalytic
polymerization unit in an oil refinery; supervisory control
Mar. 1962 First claim of direct digital control achieved on an ethylene unit in Texas
1963—1965 Series of meetings held by users/vendors to establish good practice;
IEEE/ISA support
1965 IC’s commercially available
… Computer Control systems become unwieldy to program/maintain.
1975 TDC2000 revolutionizes market; Uses CP1600 a 16 bit processor jointly
developed by Honeywell and GI.