Reducing manufacturing costs through .NET enabled device communications

  • April 21, 2010
  • Case Study
By Chuck Karwoski, President, CimQuest INGEARIn high volume medical device production, driving costs and unnecessary delays out of the production line can have significant bottom line benefits. The better the information that plant personnel have on their operations, the greater will be their ability to manage costs, output, quality, and ultimately – profitability; and some of their most valuable data lies within the programmable logic controllers (PLCs) that automate their assembly lines. Manufacturers typically deploy PLCs machine-by-machine, however, so accessing that data can be a real challenge. Over the past decade or so, recognizing the growing importance of such data to customers looking to integrate plant floor operations with enterprise applications, PLC vendors have been offering solutions to improve communications with their devices. Rockwell Automation , a world leading manufacturer of PLCs , for example, offers its customers a software connectivity solution built on the Object Linking and Embedding for Process Control (OPC) standard to enable connectivity between human machine interface (HMI) software packages and Allen Bradley PLCs. One OPC connectivity solution, which Rockwell Software offers is its RSLinx software. The RSLinx connector is an OPC Data Access 2.0 compliant server that provides communication services for Rockwell Automation’s Allen-Bradley brand of PLCs. Once a user builds an interface application with an HMI development tool, the RSLinx software would provide them the drivers and other connectivity components that enable communications with the PLC. Users are then required to purchase individual RSLinx copies for every machine on which they wanted to run their application, along with annual software maintenance fees for each copyTrien Dao, senior software engineer at an unnamed medical device manufacturing facility in the Minnesota Twin Cities region, evaluated the cost of using RSLinx server to communicate with numerous Allen Bradley PLCs deployed throughout the plant, but the fact that license and annual maintenance fees would be required for each copy set him searching for an alternative. One tool that he discovered automated the development of OPC applications. Working with OPC can be complex and requires specialized experience and the software that he discovered simplified the process of working with OPC significantly, but it still required purchase of individual RSLinx copies and maintenance fees, along with the cost of managing yet another license, so this was far from an ideal solution. Realizing an on off-the-shelf Microsoft.NET technology solution would enable him to develop an open standard HMI using user-friendly tools, he and a colleague Googled the phrase “.NET PLC driver” led him to which is the web site of CimQuest INGEAR, a Pennsylvania based company which offers Microsoft.NET based PLC communication tools for leading PLCs manufacturers, and offers runtime free distribution and deployment.“With the CimQuest INGEAR solution, once we developed the interface, all we had to do is export the DLL to any machine on which we wanted to run it. We didn’t have to pay additional fees. We have PLCs running on many machines, so not having to buy additional licenses for each one is a tremendous cost savings – definitely in the six figures,” said Dao.The INGEAR.NET software from CimQuest is a set of runtime free class libraries that simplify building, developing and deploying connected systems for manufacturing applications using Visual Basic or Visual Studio .NET. It uses only three primary classes of .NET code: one of which manages the PLC, one manages the data that are read from or written to that PLC, and one manages groupings of methods, properties and events to optimize read/write operations on a collection. It includes a direct Ethernet communication channel to the PLCs enabling developers to write HMI interfaces to PLC controls or to acquire data from them. It requires no additional third-party components, drivers, APIs or tools, such as OPC Servers. This simple programming model contributes to faster response times and ease of use.“In addition to the cost savings, we found response time for the applications we created with INGEAR to be much faster – by seconds - than other applications we have created,” said Dao, reporting also that he fully expects such significant improvements in response time to improve output as well.In the CimQuest software Dao found both a solution which eliminated runtime fees entirely by enabling connectivity without RSLinx. At the same time, the solution overcoming the complexity of OPC, simply by eliminating the need for it and utilizing the familiar .NET programming. Using .NET brought with it the added advantage of enabling him to assign programming task to.NET programmers who did not necessarily have an understanding of PLC control logic. Allen Bradley brand PLCs are only one of the number of brands that Dao is looking to communicate with. So impressed was he with the economics and the performance on the Allen Bradley PLCs, he is now evaluating expansion of runtime free communications development across other brands of PLCs that are deployed in the plant, and expects similar gains in cost reduction, response time improvement and ease of use. Learn More

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