Integrated Safety Systems Winning Out

May 4, 2009
The push and pull of integrated vs. separate safety and control systems is subsiding. In spite of some concerns, safety is getting integrated into control systems.

Argentina’s chemical manufacturer, Atanor, opened a new plant in the province of Rio Tercero to produce hydrogen peroxide. The plant is expected to produce enough of the chemical to meet Argentina’s total domestic demand and eventually export to neighboring countries. For its control system, the company decided to deploy ABB’s System 800xA, a system with fully integrated safety compliant with the IEC 61508 and IEC 61511 safety standards promulgated by the International Electrotechnical Commission. The system spans the entire safety loop, including controllers, field input devices, input/output (I/O) modules and field actuators.

The goal of using an integrated control and safety system was to improve control system reliability, increase uptime, lower costs with quicker start-up and shut-down, and optimize performance. According to Odel Protti, general manager of the plant, the system gave engineers better visibility into both control and safety than would a set-up based on separate safety and control systems. “It shows us tendencies, graphics and lists of events happening at any given time,” says Protti. “It gives us many tools with which we are able to solve problems that may be occurring in the process.”

The integrated control and safety system allows engineers to shut down the plant in less than five minutes, if needed. A single operator can now complete a plant start-up in less than 10 minutes. Protti notes that plant safety is actually enhanced because engineers and operators only need to be trained to operate one system, which saves the engineering team time and money.

One way or another, safety is getting integrated into control systems. Sometimes, it’s a matter of simply sharing data between safety and control, but increasingly, safety and control are merging into one system. The price is higher for the control system, but that can be leveraged against reduced installation costs, lower maintenance expenses and increased uptime.

Control and safety teams are also merging. Some see that as a problem; others see it as enhanced safety with reduced personnel. On the downside: the priorities of control and safety sometimes conflict, and cyber security becomes an issue.

Developments in technology have accelerated the move to integrate control and safety. For one, technology now provides the ability to run separate control and safety functions using the same hardware and software. “Many believe this is a new concept, but what’s new is the technology available to integrate,” says Luis Duran, who works in business development for safety systems for ABB America Inc., in Norwalk, Conn. “Twenty years ago, you would not think of running safety control on a PLC (programmable logic controller). Now you can have truly independent safety control and process control even if they’re on the same network.”

The benefits of incorporating safety into the control system have pushed companies to adopt integrated systems. “There is more pressure on manufacturing to put safety on to control. They’re not separate functions any longer,” says Dave Reynolds, product manager at GE Fanuc Intelligent Platforms, a controls vendor based in Charlottesville, Va. “Downsizing is starting to blend safety and control, so process control engineers are now more aware of safety.”

Proponents of integrated safety argue that integration actually improves safety, so the move to integrate safety and control doesn’t mean there is less emphasis on safety. If anything, safety has become more of a concern in recent years, not just to protect personnel but also to protect the image of the company. “Safety is becoming a bigger and bigger issue. You have a lot of companies measuring themselves on incidents per month,” says Simon Jacobson, research director, AMR Research Inc., in Boston. “Consumers don’t want to find out that 80 people died making their car.”

There are a wide range of benefits that come with integrated safety and control. For one, operators get a wider view of plant operations. “The benefits are better visibility of machinery and a whole variety of status information,” says Jim Frider, manager for mobile solutions at manufacturing software supplier Wonderware, an Invensys company in Lake Forest Calif. “It’s good for everyone involved. You get one version of the truth and it allows companies to develop hybrid systems that provide a holistic view of the plant. It’s also cheaper.”

Integrating safety and control yields another benefit in discrete manufacturing, in that control engineers will be able to understand and operate the safety system. “There is a change in the way people view safety in machines. People want a more integrated support system. They don’t want to support two systems and train people on two systems,” says Mike Miller, business development for safety business at controls vendor Rockwell Automation Inc., in Milwaukee.

Cost is also a large factor for machine safety. An integrated safety and control system can come with higher initial costs. “The new integrated systems can be substantially more than the existing solutions, so a clear advantage in performance, functionality or business need must be identified,” says Dave Collins, product manager of machine safety products at Schneider Electric, another automation vendor in Palatine, Ill.

There are a number of savings plants are finding to offset the added expense of an integrated system. The savings come in implementation, staff reduction and increased uptime. “You can make a machine more efficient because of safety integration,” says Dan Hornbeck, safety development manager at Rockwell. “I’ve gone through my pneumatics and I’ve reduced air leaks and that has saved a ton of money. So integration helps the bottom line.”

Another benefit of an integrated system is that it can be replicated across many plants. Separate control and safety systems are not as portable. An integrated system can be exported to other machines or to additional plants. Best practices can be developed and implemented machine-to-machine, plant-to-plant. “Our safety control code can be exported out of one project to another machine,” says Kurt Wadowick, I/O products specialist at Beckhoff Automation, a Burnsville, Minn.-based automation supplier.

The integration of safety and control allows the control engineer access to the safety system. In many cases, the control engineering team works closely with the safety engineering team, and in some cases, the responsibility for safety passes on to the control team. “Moving to integrated safety is an education for all involved,” says Robert
Muehlfellner, director of automation technology at B&R Industrial Automation Corp.  a Roswell, Ga., automation vendor. “Control engineers didn’t used to worry about safety.

Even though the control engineer will have access to safety, many plants insist on maintaining separate teams. “I think there will still be a need for separate teams for safety and control,” says Wadowick, of Beckhoff. “Even though safety is in the control system, you still have to do hazard analysis and zone guarding, so if you open one part of a machine, the machine can still operate.”

Even though there is momentum toward integrated safety and control, many in the industry point out downsides to integration, especially with systems completely integrated in one box. “Some people are concerned about the failure of electronics,” says Tim Palmer, automation consultant at vendor Siemens Energy & Automation Inc., in Alpharetta, Ga. “The design is rock solid, but it still causes concern.”

One of the fears is that someone changing a control setting may inadvertently alter a safety setting. “If you go into your computer to change something and safety is in the same box, you’ve opened a Pandora’s box. How do you know if you’ve changed safety?” asks Charlie Fialkowski, national process safety manager at Siemens.

Fialkowski also points to the issue of cyber security. One of the potential challenges with integrated safety is the vulnerability to cyber attack. If safety is on the same network as control, it is potentially exposed to the Internet. “The process control is going to have some connection to the Internet, and that’s where the evil resides,” says Fialkowski.

While the safety standards have blessed integrated safety, some vendors take a decidedly strict view of control and safety separation. “Safety standard IEC 61508 states that the control system should be separate and independent from the safety-related system,” says Erik deGroot, marketing manager for safety management systems at automation supplier Honeywell Process Solutions, in Phoenix. “The more conservative users go for completely separated control and safety. If you use the same hardware, the control system should be treated as a safety-related system.”

However you look at it, the trend is strongly in favor of integrating control and safety. Whether it’s a matter of sharing data or running both control and safety from the same box, control engineers are seeing safety functions enter their realm. And the majority claim that safety has been enhanced as it merges with control.

Related Sidebar - Safety Integration Comes With BenefitsTo read the article accompanying this story, go Sidebar - Levels Of IntegrationTo read the article accompanying this story, go

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