1 Introduction Logic controller PLC can be compiled into the hands of the domestic industrial control has been nearly a decade, the early composition of PLC due to hardware and software environment, the limitations of its scope of application set by two constraints. In recent years, with the microelectronic technology and rapid development of computer technology, PLC product a high degree of integration of the computer industry with the latest technology into the classic theory of industrial automation, functionality and performance in the indicators to be greatly enriched and improved to break through the traditional PLC concept, in the small control area greatly expanded its range of applications. In the context of specific, cost-effective PLC has become the most prominent new feature.
AB is a world-renowned manufacturer of industrial products, its industry Automation Control products for its high performance, high reliability in industrial control field has its specific status. AB's PLC products is the leader in the field of the product. AB This paper will introduce the company's latest product in a southern 3X125MW PLC unit power plant auxiliary equipment in the practical application example, to introduce new products, advanced PLC functions and performance.
2 Products United States AB's latest model of SLC500/03PLC system is the field of PLC products in the more advanced models of the two, in addition to a conventional PLC product's basic performance, it also has the following unique features:
* Powerful input / output signals to support capacity, I / O interface, part of the support 960 discrete points;
* Rich simple, integrated instruction, the processor instruction set 71, is easy to learn easy of application and promotion;
* Multi-level work status indicators show the system to facilitate on-site operating personnel working condition at a glance;
* High reliability of performance design, ensure normal working conditions, maintenance of the system is the lowest.
3 process Process as a power plant in two
important part of some chemical water treatment plant in the automatic control system has a pivotal position. It's working status will directly affect the safety of the boiler system and economy, and affect the stability of the whole plant work and reliability. Electrical control of water chemistry of various control Valve And the interlock switch more of them work any part of the state of stability and reliability of water will control some of the chemical effects produced with both hands.
For such a practical situation, we control in the chemical part of the water used by the PLC program control system configuration, use the AB, high-performance PLC products SLC-500/03, thus completing the chemical treatment section start, stop, pause, and then start and the associated solenoid valve boxes, Fans Pump control. Chemical part of the running water (bottled water) and the regeneration of instruction all automatically. When a water treatment equipment failure, by the detection Meter Signal to the device from the system solution of water column, after judging, confirmed with regeneration conditions, the automatic regeneration. Regeneration process has been completed, water quality, the device automatically after passing into the water system, restore water to the island.