Smar: First In Fieldbus

Today, with fieldbus being adopted at plants in a wide range of industries around the world, it's easy to forget that standards issues and vendor disagreements once caused end users to question whether the technology would ever be "real." Despite this situation, one company – Smar International – staked its future on fieldbus, and subsequently helped the technology become a driving force in plant automation.

Established in April 1974, Smar took its name from the initials of its founders, Mr. Mauro Sponchiado and Mr. Jose Martinussi. The company's first area of business was servicing steam turbines in sugar refineries. Smar added in-house electronics expertise when electronic speed regulators were introduced for steam turbines in 1978. It soon developed electronic controls for cane cutters and crushers as well.

Smar went on to develop a full line of process control instruments, becoming a multi-national company with operations in key locations around the world. Smar entered the global controls and instrumentation market in 1988 when it introduced a line of smart pressure and temperature transmitters at the ISA show in Houston. It captured the industry's attention in 1991 by unveiling its LD301 pressure transmitter, which incorporated HART protocol, PID control and flow integration in a single device; and again in 1994, with the release of the LD302 transmitter, the world's first commercial fieldbus product.

During the early 1980s, Smar was one of the initial suppliers to recognize the potential of microprocessors for use in field instrumentation. Indeed, Smar's founders openly embraced technical innovation, allowing the company to explore new opportunities in digital instruments while larger, traditional competitors took a more conservative approach.

According to Smar International Vice President Carlos Liboni, the company was well suited to develop some of the industry's first "smart" field instruments. "Smar was born as a single company – not as a group of different organizations with diverse backgrounds that were acquired and grouped together under a common banner," said Liboni. "This led to a tradition of working together as a team across technical disciplines, and without internal conflicts, to solve the customer's problems."

Smar's early involvement in intelligent instrumentation helped make it a pioneer in "fieldbus" technology. The company's advancements were aided by its in-house capabilities for integrated circuit design, as well as its experience with networking and software. However, Smar's engineers took a view of fieldbus different from many of their counterparts at other companies. Liboni said, "While some automation vendors looked at fieldbus as just a "digital 4-20 mA," we realized that it was, in fact, an entirely new system architecture."

He continued, "Unlike the major suppliers, Smar had no vested interest in proprietary technologies or legacy platforms, and therefore, we were able to adopt the fieldbus architecture wholesale including High Speed Ethernet (HSE) and the standard function block diagram programming language. We developed fieldbus solutions enabling users to employ the technology as it was intended. For example, we applied the concept of decentralized control for single-loop integrity to a greater extent than others.

"Plus, Smar's roots are in process control, and this expertise resulted in our technology being very focused on applications."

With the advent of fieldbus, the control industry was seeking uniformity for the technology, with the objective of establishing a single, international standard. Smar contributed to this long, and often difficult process, serving on the Instrumentation, Systems, and Automation Society (ISA) SP50 committee and participating in organizations such as the International Fieldbus Consortium (IFC), InterOperable Systems Project (ISP), and WorldFIP.

In 1995, the members of ISP and WorldFIP North America joined together to form the Fieldbus Foundation™, and Smar was one of the companies that helped lay the groundwork for the new, global consortium. "All of the leading automation vendors, including Smar, recognized that we needed to work together if fieldbus was to gain acceptance among end users," said Liboni. "By establishing the Fieldbus Foundation, we hoped to create an open, neutral environment where the technology could be further developed and standardized."

Throughout the late 1990s, Smar's extensive experience in fieldbus produced a host of important technology milestones. The company's research group designed microprocessors that lowered the power consumption of fieldbus devices. It also developed the fieldbus instantiation capability and a backup Link Active Scheduler (LAS) that can reside in field devices, and created a device configuration tool eliminating the need for proprietary files.

According to Liboni, Smar's emphasis on fieldbus is a source of pride within the company. "Our engineers are truly dedicated to advancing the technology, and this has resulted in many industry 'firsts,' including the design of compact, high performance smart transmitters; the incorporation of control and mathematical functions in field devices; and the development of high-performance chips for the fieldbus physical layer.

"Most recently, we introduced the first commercial products implementing the Fieldbus Foundation's HSE specifications and new Flexible Function Block technology," he added.

Aside from its history of technical innovation, Smar has been at the forefront of putting fieldbus to work in a wide range of process automation applications. The company introduced control in field devices at Deten Chemicals in 1994, and pioneered boiler control with fieldbus at Seattle Steam in 1996. This year, it undertook the first fieldbus installation in the nuclear power industry at Duke Power's Oconee nuclear station.

Smar also opened the door to commercial applications for HSE technology when Merisol Chemicals implemented its SYSTEM302 solution at the Greens Bayou refinery near Houston, Texas, in 2000.

Liboni believes the "next frontier" for fieldbus development is in the area of host computer software. One example: a low-level data access paradigm devised by Smar engineers isolates software from the complexity of fieldbus communication and management. Additionally, the company has designed a high-level client/server interface performing a comparable function for fieldbus configuration. This concept is very similar to OLE for Process Control (OPC), but performs all the functions required by fieldbus not provided by OPC. Smar has also employed ADP at the core of its asset management software in order to bring fieldbus information into the IT environment using web technologies.

From the beginning, Smar recognized that different bus protocols would be required to support the vast array of control applications in process and discrete manufacturing. "Though the ideal is a single bus in the plant, fieldbus will likely have to co-exist with a large installed base of existing technologies – at least for the time being," said Liboni. "However, bus technologies should be mixed with care since the complexity of integrating many buses may outweigh the benefits of adding a second or third technology."

To address this need, Smar has developed a wide range of local and field-mounted converters for analog, discrete and even pneumatic signals. The information architecture in SYSTEM302 also includes a software architecture based on OPC allowing integration of other bus technologies, legacy DCS, and proprietary subsystems.

Liboni indicated that major automation providers are now working together to share bus technologies in an effort to better serve the needs of customers. For instance, Smar has established technology alliances with other industry leaders, including Endress+Hauser and Rockwell Automation, in order to assure that a wide spectrum of devices are made available to the end user community.

In addition to its active role in the Fieldbus Foundation, Smar is involved in other major bus initiatives, including the HART Foundation and Profibus Trade Organization. The company manufactures transmitters, positioners and converters compliant with the technologies of both organizations. Furthermore, Smar is the world's largest manufacturer of HART chips, producing integrated circuits used in HART devices from about 80 manufacturers.

"Smar is committed to supporting different customer requirements around the globe. This includes integrating the large installed base of existing products found in most plants," said Liboni.

Smar's approach to digital network integration is evidenced by its new HI302 interface module, which integrates HART devices into FOUNDATION fieldbus networks. The HI302 is designed help users protect their installed HART investment when migrating to the robust functionality of FOUNDATION fieldbus. Smar's HART offering also includes a handheld configuration tool based on the Palm platform, serial interfaces for RS232 and USB, and configuration software that runs Windows, Unix, Linux, etc.

In addition, Smar developed an IEC 61158 communication chip for use in its fieldbus devices that is compatible with both FOUNDATION fieldbus H1 and PROFIBUS-PA. It also developed one of the first registered FOUNDATION fieldbus linking devices. The Smar DFI302 not only supports FOUNDATION fieldbus H1 segments, but also provides an additional port for Modbus communications. This allows the DFI to act as a Modbus Master or Slave device providing flexibility unmatched by other systems.

Although a small company compared to its major worldwide competitors, Smar has gained considerable recognition from its status as First in Fieldbus. "It's encouraging that we are now doing business with customers who previously didn't even have time to meet with us," noted Liboni. “It’s exciting to see the benefits FOUNDATION fieldbus technology provides customers each and every day. Decreased installation costs, shorter implementation cycles, better control performance and increased profits. It’s rewarding to know we helped make it happen.”