Kepware's LinkMaster covers the Paper Plants Problem!...

The Georgia Pacific paper mill in Yalova, Turkey faced several problems. In the water treatment portion of the paper plant, data needed to be fed into an ABB Advant OCS using a Siemens PLC. At first, they requested to connect in a classic way with a Siemens PLC to an ABB Advant OCS using Profibus. This type of Profibus connection tends to be very costly and time consuming to set up, however. Mill production must stop each time that the Profibus connection and all of its programming requirements is coupled with a DCS controller (which must restart each time it connects to a slave). ASP Otomasyon needed to come up with an affordable /robust solution that kept up with the rate of the data feed. ASP Otomasyon has many years of experience in the paper industry and approached this problem by applying the use of Kepware Technologies' LinkMaster and KEPServerEX OPC Server with plug-in driver for Siemens. The paper mills' request of transferring data from PLC to DCS is common and understandable, the DCS has complex structures and operators prefer to observe and control every item from the DCS. With this in mind, ASP deployed the KEPServerEX application to read all the tags from the Siemens PLC. Then we incorporated the use of LinkMaster to link this PLC data to the DCS. LinkMaster provides a means of bridging data from one server application to another and it required no programming, LinkMaster has a simple "Drag and Drop" method that will create links, plus Built-in scaling, user-access manager, error tracking, and write optimization capabilities, providing total control of data flow and application access. Link groups are then created to form collections of OPC items that will be moved between OPC servers at a specified rate. Using multiple Link Groups, LinkMaster allows the control of how fast data is transferred from one OPC server to another. By using Link Groups with different update rates, the data transfers can be tailored to the needs of the application. While one item may need to be sent at high speed, other items in the application may need slower update rates. adjustable Update Rate in Link Groups can be used to reduce network traffic and increased reliability of the overall application. During implementation of this project, ASP Otomasyon faced one problem: When the tag delivers new information, LinkMaster keeps the tag engaged (at DCS) while writing the new value. The data would change every second and while the data was changing, the tag and the DCS were still engaged. This resulted in the operator being unable to select the tag while the data exchange was occurring. This was solved by creating and using new variables, they would then be forwarded inside the DCS database. By doing this, the operator could reach the original tags while new tags were being read and written. The project was completed on time, within budget and is still working very well for the client. Return to Kepware Case Studies Page »»