Distributed control system: Difference between revisions

Revision as of 12:37, 12 July 2019

Revision as of 13:52, 18 September 2019

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The drive toward openness in the 1980s gained momentum through the 1990s with the increased adoption of [[commercial off-the-shelf]] (COTS) components and IT standards. Probably the biggest transition undertaken during this time was the move from the UNIX operating system to the Windows environment. While the realm of the real time operating system ([[RTOS]]) for control applications remains dominated by real time commercial variants of UNIX or proprietary operating systems, everything above real-time control has made the transition to Windows.

The introduction of Microsoft at the desktop and server layers resulted in the development of technologies such as [[OLE for process control|OLE for process control (OPC)]], which is now a de facto industry connectivity standard. Internet technology also began to make its mark in automation and the world, with most DCS HMI supporting Internet connectivity. The 1990s were also known for the "Fieldbus Wars", where rival organizations competed to define what would become the IEC [[fieldbus]] standard for digital communication with field instrumentation instead of 4–20 milliamp analog communications. The first fieldbus installations occurred in the 1990s. Towards the end of the decade, the technology began to develop significant momentum, with the market consolidated around Ethernet I/P, Foundation Fieldbus and Profibus PA for process automation applications. Some suppliers built new systems from the ground up to maximize functionality with fieldbus, such as [[Rockwell Automation|Rockwell]] PlantPAx System, [[Honeywell]] with [[Experion]] & Plantscape [[SCADA]] systems, [[ABB Group|ABB]] with System 800xA,<ref>{{cite web|url=http://www.abb.com/product/us/9AAC115756.aspx|title=ABB System 800xA - process, electrical, safety, telecoms in one system|website=www.abb.com}}</ref> Emerson Process Management<ref>[http://easydeltav.com] [[Emerson Process Management]]</ref> with the [[Emerson Process Management]] [[DeltaV]] control system, [[Siemens]] with the SPPA-T3000<ref>[http://www.energy.siemens.com/hq/en/automation/power-generation/sppa-t3000.htm] SPPA-T3000</ref> or [[Simatic PCS 7]],<ref>{{cite web |url=http://pcs.khe.siemens.com/index.aspx?nr%3D1075 |title=Archived copy |accessdate=2007-03-29 |deadurlurl-status=yesdead |archiveurl=https://web.archive.org/web/20070329065215/http://pcs.khe.siemens.com/index.aspx?nr=1075 |archivedate=2007-03-29 |df= }} Simatic PCS 7</ref> Forbes Marshall<ref>[http://www.forbesmarshall.com/fm_micro/DCS/Products1.aspx?flag=1&id=dcs&pid=551&prodName=Microcon+%20Distributed%20Control%20System(DCS)] [[Forbes Marshall]]</ref> with the Microcon+ control system and [[Azbil Corporation]]<ref>[http://www.azbil.com] Azbil Corporation</ref> with the [[Harmonas-DEO]] system. Fieldbus technics have been used to integrate machine, drives, quality and [[condition monitoring]] applications to one DCS with Valmet DNA system.<ref name="Valmet" />

The impact of COTS, however, was most pronounced at the hardware layer. For years, the primary business of DCS suppliers had been the supply of large amounts of hardware, particularly I/O and controllers. The initial proliferation of DCSs required the installation of prodigious amounts of this hardware, most of it manufactured from the bottom up by DCS suppliers. Standard computer components from manufacturers such as Intel and Motorola, however, made it cost prohibitive for DCS suppliers to continue making their own components, workstations, and networking hardware.