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9-16-2004--- DIRECT PLC-TO-ENTERPRISE INTERACTIVITY
by William Glover, President, INTEWORX.NET, INC.

Managing production and resources simultaneously

Today's aggressive market environment demands that plant processes be as accurate and efficient as possible. This requires the collaboration of two vastly diverse systems. The shop-floor control systems keep operations moving quickly and produce high-quality products at a competitive cost, in a safe working environment. IT uses data-processing services to manage the efficient and effective delivery of goods and services. It provides support to evaluate, obtain, develop and modify systems to fit the specified needs of various operating units.

The interdependent relationship between the shop-floor control system and the information-processing unit makes success possible only when important data can flow freely between the two divisions. This presents the problem of how to transfer large amounts of information from the plant floor into the enterprise system and back out to the plant-floor control units in an efficient manner.

Communicating information to the enterprise

Problems associated with the internal flow of information are nothing new. However, engineers, plant managers and IT personnel are becoming more concerned with the efficiency of this flow, the ease of storage and retrieval, and the interactivity between systems. As processes are becoming more recipe-oriented, using multiple formulas and set-points to carry out operations, enterprise databases are emerging as the best way to store and share the overwhelming amounts of information needed and generated on a day-to-day basis.

There are many functional advantages to using databases to store, retrieve and send information. Databases allow for convenient storage, easy retrieval, speedy operations and organized displays. Recipes from PLCs can be programmed and changed from the database, which is much easier than reprogramming a PLC directly. Settings can also be recorded in the database and sent back to the PLC for future operations, eliminating unnecessary reprogramming altogether.

Traditionally, PLCs and databases have communicated indirectly through SCADA packages. This provides a viable solution to the problem of getting information from the plant floor into the enterprise system. For some users, however, the intricacy and expense of SCADA packages may negate the purpose of using a database storage and retrieval system. Database systems are meant to be more efficient, convenient and interactive. However, the complexity of many SCADA packages makes them inefficient and slow, and their architecture prohibits interactivity.

Proactive data-collection and PLC control

As the passive and inefficient information flow between PLCs and their enterprise systems is becoming a concern to industrial leaders, unique solutions are beginning to emerge. AutomationDirect's DirectLOGIC PLCs or WinPLCs, for example, can communicate directly with enterprise database systems using INTEWORX.NET's DataWorx Professional software packages. Unlike traditional SCADA packages, DataWorx Professional actually acts as a translator, rather than a go-between. It translates the PLC's original data into SQL statements, so the PLC and database can communicate in the same language, eliminating the need for expensive third-party packages and unnecessary programming.

Unlike SCADA solutions, the Professional software packages allow the PLC to have complete control over its information's storage and retrieval. Using the report-by-exception method, PLCs are able to send data to the enterprise system only when necessary, which eases network traffic. These proactive data-collection tools also enable the user to easily and quickly define database operations to the PLC, so it is able to conduct database operations on its own. Perhaps the most unique feature of these packages is that they allow the user to retrieve information from the database and send it back to the PLC. These innovative systems give the PLC direct interaction with the database, making the process more efficient and making the jobs of those on the floor much easier.

For more information on INTEWORX.NET, Inc., or the DataWorx Professional software packages, visit www.inteworx.net or call (770) 886-6166.

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