Soon after its introduction in 1997, Simatic PCS proved to be a trendsetter in the market. Since then, Siemens' process control system has become something of a standard in many process sectors.
More than just a classic control system
Siemens says that Simatic PCS7 is still the only process control system on the market that is more than just a classic control system. It has a much wider area of application because of its continuity and a degree of integration for the whole automation for preliminary, adjacent and subordinate processes (for example feeding material or packaging). The reason for this, is the use of the Simatic controller, which is able to facilitate effective control tasks in the world of programmable control systems and is best suited to control technology tasks. The use of standards in the system, flexibility, modularity, scalability and openness together with several economic advantages have all contributed to its success. An additional system advantage of PCS7 is that it is based on the 'Totally integrated automation' concept, for which Siemens Automation and Drives supplies a wide range of components.
Universal yet specialised
At the beginning of this year, the 2000th Simatic PCS7 process control system was supplied by the electronics factory in Karlsruhe, Germany. More than a third of the systems supplied are being used for very different applications in the petrochemical, chemicals, fine chemicals and pharmaceutical industries. In other words, they are being used in industries where there is a diverse range of requirements and applications. Yet even here the talk is turning more and more to uniform operation, a single platform. The high degree of flexibility and the integration of PCS7 are certainly two major reasons why this system has been so successful on the market. Through its modular structure PCS7 excels on all levels. Whether it is the operator stations, the controller, the networking, the peripherals - or the field, the system offers a wide range of opportunities. These can be adapted to meet the performance and environmental requirements of many tasks. The comprehensive engineering system offers efficient configuration tools in a standardised, trusted and easy to use Windows NT environment. They can be used for both count and batch processes (with optional PCS7-Batch flexible package). In addition to the universal applications, there is enough free space on the PCS7 - thanks to its openness for it to be adapted to meet special needs. These include specialist or external hardware with which it must be integrated, or the use of user-specific functional models, operating systems and programs. This openness approach is based on the industrial standards for data exchange and application interfaces. Current process data for specific process optimisation programs is also accessible.
Universal redundancy
The new redundant S7-417H controllers make a universal redundancy concept possible for redundant systems at all levels. These include the operator stations and their redundant OS servers as well as the quick redundant Fast-Ethernet on the communications level. This redundancy concept is now also being extended into the field. The decentralised ET 200M input/output modules can be connected to a redundant Profibus with two intelligent interface IM153 modules.
Connection to Profibus-PA is via the DP/PA link. The configuration is transparent and is implemented without additional engineering work - unlike most redundant structures. The use of optical networking components means that large distances between the I/O modules are not a problem.
The Profibus concept with the profile DP for high-speed applications and the PA profile for applications in the field makes the connection of many Profibus-PA field instruments possible without performance loss (even in Ex applications). Typically with five to six field instruments on each PA phase and up to five PA phases on every DP/PA link up to 31 field instruments can be connected via a bus to each DP/PA link. As several DP/PA links are possible per automation station, several hundred field instruments can be connected to one controller.
Everything at a glance, even with large systems
Until now systems fitted with PCS7, have as a rule been small or medium-sized. Here the operation and observation has proved to be particularly user-friendly, efficient and reliable. The clearly structured and flexibly designed operation features guarantee reliable process management with their user-friendly functions and operation. They also facilitate effective training as well as simpler entry for the system operator. With the new expanded PCS7 multi-client/multi-server architecture, systems with considerably larger volumes of equipment can now be operated with the same degree of ease and operational safety.
| Tel: | +27 11 652 2000 |
| Email: | [email protected] |
| www: | www.siemens.co.za |
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