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July 2009

Factory Automation

Achieving interoperability

The OPC driver is a key component of our production processes in addressing device-to-device and bus-to-bus interoperability needs

By John Haydock

Rea Magnet Wire manufactures wire. It is not high-tech, and the product is not remarkable.

However, the company has been in business since the 1930s and still needs to maintain a competitive edge using technology and streamlining production processes. A significant part of that strategy is automation and achieving device-to-device and bus-to-bus interoperability.

The main product is film insulated magnet wire. It is copper or aluminum wire with an insulating layer that is thin and temperature-resistant. It is for winding wire coils that serve to create magnetic fields used in motors, transformers, and electronic devices.

One area of responsibility entails managing our plant’s communication software. We use an OPC communications driver to help connect a system that we use in several of our manufacturing plants that monitors our production equipment. The system records all data on a plant-wide basis for monitoring and tracking. This allows us to display data in real time for monitoring the plant and to save data for historical analysis. The OPC driver is a key component of our production processes in addressing our device-to-device and bus-to-bus interoperability needs.

Bus-to-bus communications

OPC Data eXchange (DX) manages the needs of device-to-device and bus-to-bus interoperability by applying the same technologies currently used by desktop applications at the device level.

By adding OPC Data Access (DA) client support to an existing OPC DA server, we end up with a DX server that not only provides access to its data, but also has the ability to gather data from other OPC DA enabled devices, being able to read from one device and write the information to another.

Bus-to-bus interoperability has helped successfully bridge the vertical communication gap between the plant floor and the control room. In the past, there have been a number of high-level and low-level bus protocols, each one written to address the differing needs and uses of the devices they were to serve.

Protocols, such as Profibus, DeviceNet, ControlNet, and many more, have been useful, but recently, there has been a growing movement towards the use of Ethernet as an industrial communication backbone, which is the case for Rea Magnet Wire.

Initially, each of these respective bus specifications underwent a rehab for use over Ethernet. The resulting Profinet, EtherNet/IP, High-Speed Ethernet Fieldbus, and BACNET/IP provided a means for customers to move smoothly from their proprietary wiring schemes to Ethernet.

However, this approach did not entirely manage the key issue of true device-to-device interoperability or more importantly bus-to-bus interoperability. While new Ethernet based protocols could coexist on the same wire, there was still no way to get data from a Profinet device directly into an EtherNet/IP device.

OPC driver plays a key role

The OPC driver is a key piece of our system. We use it to make the communications connection between the software we use to display the data, sold by GE Fanuc (iFIX and Proficy Historian). We have standardized on Kepware and their reseller partner, Software Toolbox.

Our process data system has been evolving for us, over the last 10 years. Early on, we were using PCs on the plant floor and a multitude of different communications drivers to connect to the various PLCs.

A couple things have changed in the last few years that made this system more robust for us—an expansion of Ethernet technologies and controls tools now available for us to connect to plant floor devices over the Internet, which enables Rea Magnet Wire to merge multiple plant floor machines onto a single server.

Another change has been standardizing on a communication driver that offers a profusion of connectivity to plant floor devices. This simplified our system model. For example, we are able to communicate from the plant floor devices through Ethernet to a server and its single suite of communications drivers to move data into the software.

The result has been a lifesaver in terms of efficiency, but getting there can be complex in some older plants where we are dealing with some legacy equipment.

We have about 100 devices per plant ranging from a more current PLC with Ethernet communication capability down to single loop temperature controllers. These older devices add difficulty. While the OPC driver does not remove all of the difficulty, our provider has typically been able to provide a solution.

Managing change in long run

Rea Magnet Wire has been in business long enough that we actually predate the computer. That has meant adapting to lots of change. Sometimes the change is difficult to manage. There are some recent challenges we have had to overcome resulting from the complexity inherent in globalization. Two years ago, we purchased one of our competitors in the North American market. In recent years, we have seen shrinkage of the magnet wire market in North America because of pressure from motor manufacturers moving to China. The pressure to reduce production capacity fueled the need for the purchase. Magnet wire has become a commodity product with many competitive pressures from offshore as well as in North America. When this acquisition took place, our executives recognized the need to distinguish ourselves to our customers. One of our strengths as a company has been the use of IT in the manufacturing process, which has become a competitive advantage.

Thus, we acquired two plants, one in Fort Wayne, Ind., and one in Mexico. It has been a priority for our executives to implement their plant floor manufacturing systems in these two plants. The information we now receive from our manufacturing process gives us the ability to better manage our process and be more efficient, creating a competitive advantage.

We have taken our Process Data System model that has evolved over time and rapidly deployed it into the two new plants. The role the OPC driver plays was key for us to be able to deploy rapidly our system in those plants.

With this expansion, new challenges have arisen because we now have five plants running this system in North America. Keeping up with server obsolescence on a four-year cycle becomes fairly involved, not to mention advances in the software and keeping software updates in place.

We have been heavily involved in manufacturing in Mexico over the last year to year-and-a-half and find there is a distinct challenge there, much of which is language-related. Many of our colleagues in Mexico are proficient in English and are well versed in technology—Ethernet, PLCs, etc. However, it becomes difficult when a complex problem exists. Trying to discern the problem and troubleshoot through the translation of the language can be difficult. Often it requires a photograph to diagnose the problem.

With the reach of this system into Mexico, it is now global in scope. The system gives the users the ability to visualize the manufacturing processes in real time in all five of our plants. For example, I can sit in my plant in Fort Wayne and see live data in Mexico. The OPC server plays a key role in the chain to give us this ability for global visualization because it allows the data to flow from the plant floor to the local server we use to provide the visualization.

Data exists on a server in each plant. All we have done is create the visualization stream that points to that data over the network. It seems marvelous when you look at it, but it was relatively simple for us to build the global view. Because our system had evolved over time, we had done a lot of work standardizing our design. Simple things like naming conventions require a standard practice to prevent having a collision when multiple plants tie together.

We spent a lot of time and effort coming up with a standard design with no vision at all that at some point in the future we were going to double the size of our company, and add two plants almost overnight. Having done this in advance, we were able to easily export what we had in three plants to two new plants without having to redesign the system.

Innovation via technology

As the company recognizes the product it makes is not changing or developing technologically, we still need to be competitive in the marketplace by differentiating in other ways, such as in service and quality. The executives recognize IT is a way to differentiate the company. There is a huge interest in doing business and commercializing our business through technology such as our OPC servers. We have expanded to use the web to develop a competitive edge.

The company was perceptive enough to have the foresight to use software communications technology and to proactively leverage it for growth and expansion.

Our IT department reorganized about five years ago to accommodate the need to merge IT and the controls engineering environments. Plant engineering is now a part of the IT department, where we spend as much time interfacing with network management as we do our plant operations management. That has greatly increased efficiencies in both areas.

ABOUT THE AUTHOR

John Haydock (jhaydock@reawire.com) is control systems engineering manager at Rea Magnet Wire in Fort Wayne. He has a BS and an MS in electrical engineering and was a nuclear submarine officer in the U.S. Navy. Haydock is an ISA member.