Smart devices and linkages

In the northern Netherlands, high-quality magnesium chloride salt deposits lie 1,500 meters below the surface. About half a million tons are extracted every year by Dutch chemical corporation Nedmag Industries Mining and Manufacturing. Shell established the Nedmag site in 1979 because of its extensive natural gas reservoirs.

By Renee Robbins, Control Engineering October 1, 2008

In the northern Netherlands, high-quality magnesium chloride salt deposits lie 1,500 meters below the surface. About half a million tons are extracted every year by Dutch chemical corporation Nedmag Industries Mining and Manufacturing. Shell established the Nedmag site in 1979 because of its extensive natural gas reservoirs. In 1994, the petrochemical corporation sold the mine and associated plants, and the chemical business began operating under the name of Nedmag. In 2001, the magnesium specialists extended their production by including the neighboring calcium chloride fabrication.

To connect device management software to HART devices and Siemens Remote I/O, Nedmag needed FDT technology and a gateway from Trebing & Himstedt.

The facilities and physical plants of Nedmag evolved with the company, growing over time into an automation mix of assorted controls, process control systems, remote I/Os, and field devices of any kind and origin across all levels. The widely various components also used different communication protocols and device integration technologies. Vertical system integration of any kind was a real challenge—a challenge met and conquered by the use of FDT technology, a highly versatile frame application, and a clever gateway. The integrated solution saves money throughout the complete plant life cycle, and opens up the way to efficient asset management.

When Wim Zomer, Nedmag head of technical automation, joined the company, plant failures required two days of downtime before systems could be restarted. “Whenever a plant unit fails for one day, it costs us 30,000 Euros,” says Zomer. “That cost so much money, [we decided] it is more efficient to make investments to keep the plant running—which is what we did.”

Over the last few years, Nedmag has invested 8 to 10 million Euros annually in new projects and the modernization of the site’s automation network. Zomer says that’s largely because Nedmag’s division manager has one main goal: By the time he retires five years from now, he wants to have the inconsistent, patchy automation system of the three individual production plants (dry and wet production and Calmag) to be harmonized and communicating with each other.

“In the future, it is the company’s ambition to access, read and maintain all of its 4,000 intelligent HART devices from one single server and to implement modern asset management,” says Zomer.

Nedmag engineers decided they wanted to keep HART technology. “Today, a third of our devices are intelligent,” explains Zomer. “The big idea was to make all devices accessible from one central point. I made up a concept in my mind, and implementing it will keep us busy for a while.“

To find out how they could best develop their automation structure, his team began contacting various suppliers. The specific technology for device integration initially did not play a major part in their evaluation of a half dozen software packages. Ultimately, however, the Nedmag team decided that FDT technology would be the solution that suited them best, “mainly because it is far easier to use and operate compared to EDD-based applications,” says Zomer.

Need for ease of use

Ease of use is important at Nedmag. Until 1999, the company had employed its own technical service. And, because staff members often worked for the same company for 20 years, they knew every piece of equipment. Technical service today is a separate business, says Zomer, and now all this knowledge is sourced out. Another fact supporting the need for easy to use systems is that staff turnover has become much higher.

“Even relatively inexperienced workers need to understand and use the new technology. Only then can you really save costs,” says Zomer. Whenever someone from maintenance has to do work on site, for example, “two or three hours are over in no time, and in rather unpleasant working conditions of 50 to 60 °C close to the drying furnace. Dust, aggressive media, debris and deposits hamper the work. Plus, many units are mounted at places several meters’ high, making them difficult to access.”

Given these realities, says Zomer, “The costs go right through the roof; we are spending too much money on this. There is room for improvement, and in the future, we want to do a better job here. With FDT technology, we can increase availability and reduce the number of downtime periods.”

Establishing connections

There were other key objectives for Nedmag besides ease of use. An FDT frame application, for example, was required to establish point-to-point connections between devices and laptops, read the data on the laptop, and synchronize it on the server. Not every software package can do this, but Nedmag found Fieldmate, the Yokogawa assistant for device management. This integrated tool for device management reportedly is the first on the market able to communicate with all devices: It supports FDT and EDD technologies, and it does not matter what communication protocol (HART, Foundation Fieldbus or Profibus) is used.

Simple configuration was one more reason Nedmag opted for this solution. With a few quick clicks, Fieldmate enables unlimited access to all modern field devices, and considerably more efficient maintenance services. In Zomer’s words, “We, the users, like to use a single configuration tool through which we can access all remote devices. What we do not want are manufacturer-specific and time-consuming special software packages that you only get to use once a year, and which therefore no one knows how to operate.“

The benefits of FDT became clear first during the engineering phase, and additional benefits are expected later. For example, it is no longer crucial that instruments are immediately configured with the correct measurement range. Before, Nedmag needed two technicians to parameterize all instruments during commissioning. Today, the task is completed by only one worker in a shorter timeframe.

It also often happens that installation is complete and then some modification of the measurement range is required. Before, the automation team had to remove the device again and re-calibrate it. “With HART communication, [reconfiguration] has become so much easier. We are saving time and money. The higher flexibility allows us to react much better, and more quickly, to later requirements from process engineering,“ explains Zomer.

In the future, Nedmag staff will be able to access Fieldmate via an Ethernet network. “The brilliant thing about the concept is that we can use the infrastructure already existing in each room,“ says Zomer, not without some pride in his voice. Via a secure Internet connection, members of his team also will be able to connect and take action as needed during weekends from home or at night, if necessary.

Translator between the worlds

To access from a central point, the ET200M Siemens remote I/O modules connected via Profibus, and one last piece of the puzzle needed to be found: an Ethernet-to-Profibus interface. At trade show, a gateway enabling HART data transparency via the Internet was found and purchased; however, the supplier could not provide support for the Siemens Remote I/O or the Yokogawa device manager. “A lot of time was lost,” says Zomer.

So the Nedmag automation team went looking for an integrated solution, a gateway and driver from a single source and supplier. They found German communication specialists of Trebing & Himstedt. The device type manager (DTM) information for the ET200M Siemens Remote I/O had already been certified as part DTM library, so “the Ethernet-Profibus-Interface (xEPI) was up and running immediately, without any problems,” confirms Zomer.

“Without this gateway, we could not ‘see’ a single remote I/O or device in the FDT frame application. Central access would have become a very distant goal, very much beyond reach,” says Zomer. “It is key that HART over Profibus is available and accessible, independent of the system provider.“

At the moment, the Nedmag automation specialists can still only access a small part of the 4,000 instruments through HART and portable PCs, but that number is growing. Because of the positive experience with device operation via FDT, further parts of the plant will be connected in the coming years.

Right now, four pilot projects are running in the Dutch enterprise. Before the end of this year, the team plans to speed up things considerably. Automation of the sintering furnace for the main product, dead burned magnesia oxide (DBM), for example, is scheduled for 2009.

Efficient life cycle management means the right amount of maintenance work—not too much and not too little. “The detailed, comprehensive information supplied by these intelligent devices is what brings about the cost savings,“ Zomer says. Parameters can be compared and cooling water consumption can be read, for example. If the latter increases, “this points to a dirty cooler that needs to be cleaned the next night,” he says.

Author Information
Renee Robbins is Senior Editor with Control Engineering. She can be reached at .

Nedmag delivers

Nedmag, employer of about 160 people, is the leading European supplier of pure synthetic “Dead Burned Magnesium Oxide” (DBM). Last year, Nedmag sold 75 million Euros worth of DBM and magnesium and calcium chloride. Magnesium oxide, sintered at high temperatures, is used in steel and cement production. Magnesium and calcium chloride are used in oil and gas extraction, or as an animal feed additives. They also keep streets ice-free during cold seasons and, in hot places like Saudi Arabia, bind sand to the streets.