Supervisory control and data acquisition (SCADA) has been around for decades. But it shines like new for companies like Arrow Energy Pty. Ltd., a coal-seam gas company in Queensland, Australia.
More operations are noticing that SCADA’s underlying technologies, as well as the practices for applying them, have continued to evolve over the years. As a consequence, these companies see SCADA in a new light and are taking advantage of the fresh opportunities it is presenting them.
One such opportunity is quick access to data from remote locations. “The single greatest advance in SCADA is probably digital communications,” explains Gerry Browne, engineering manager at Phoenix-based Honeywell Process Solutions (www.honeywell.com/ps). “It’s never been as inexpensive or easy to get a network connection to a device anywhere in the world.”
Advances like this are making it increasingly practical for users like Arrow Energy to develop networks that link control rooms to smart field devices at remote locations. “A few years ago, field equipment would have only a serial port,” notes Browne. “Today, the same equipment might have its own Web server and methods that expose all its operating parameters. Remote data is now available immediately, allowing users to make better decisions.”
Arrow Energy is taking advantage of this ability through a Smart Cyber System built upon Honeywell’s Experion PKS SCADA system. Because information from the smart devices is accessible over the network, Arrow and its vendors now perform many supervisory control, data acquisition, and maintenance tasks remotely. For this reason, the company has embarked upon a program of “de-manning” many of the 600 wells and five facilities it currently operates in Queensland.
Not only has finding people to staff some remote locations been a continual challenge for the company, but sending technicians to others was also quite expensive. In some cases, a technician would have to book a flight and spend as long as six hours traveling to the site. As a result, updates and service could easily turn into a three- to six-day project, not counting the lead time for booking the flight.
The cost savings, flexibility in scheduling, and logistical advantages are clear, notes Greg Jones, a SCADA and data systems engineer at Arrow Energy. And it should free the resources necessary for helping the natural gas producer to grow beyond its target of 10,000 wells and 50 processing facilities.
As beneficial as easier access to SCADA information can be, Web-based networks do increase the risk of tampering by unauthorized people if they are left open. To keep access to their SCADA systems safe, Jones and his colleagues worked with their vendors to implement the necessary cyber security.
Jones says the main challenge to safe remote access is establishing procedural controls such that the staff is aware of when changes are being made and what those changes are. Any change that can affect the functioning of facilities or machinery poses a risk to operations and safety. So, there should be only one person in control of a particular part of a SCADA system at any point in time.
In the Cloud
Cloud computing is another evolving technology giving more personnel access to SCADA. By using the cloud as a repository for information and as a processing engine, operators and engineers can receive analytical information while they are on the move outside the conventional control room. “This can mean acknowledging and taking action on alarms, controlling a process from a virtual machine at a remote location, or adjusting process values in order to increase production or efficiency,” says Melinda Corley, marketing manager at InduSoft Inc. (www.indusoft.com)in Austin, Texas.
To help users do this, InduSoft has developed Web Studio, software for creating SCADA human-machine interfaces (HMIs), dashboards, and OEE (overall equipment effectiveness) interfaces. The software provides access to data from PCs, embedded devices, mobile devices, and remote web browsers.
Using the native drivers built into Web Studio, Calgary-based Vipond Controls Ltd. (www.vipondcontrols.ca) has been able to address some of the technical problems associated with offering SCADA in the cloud as a service to the oil and gas industry. In the past, the problem with Internet-based SCADA has been that the Internet protocol and Web browsers were not designed for real-time data and control. Users would have to submit requests and then wait for a response, or they would have to press a refresh button to retrieve the most recent data. These systems were cumbersome to use for changing set points or viewing trends in the process.
The native drivers in Web Studio solve that problem by allowing Vispond Control’s cloud-based iSCADA service to connect to remote terminal units (RTUs), pump controllers, and facility PLCs, and offer a real-time HMI look and feel.
Alleviating Pain Points
Oil and gas is not the only industry benefiting from Web-based SCADA. Water providers and wastewater handlers are too. An example is the Cobb County Water System (CCWS) in suburban Atlanta, which replaced its 12-year-old SCADA system used to oversee its assets throughout the 345-square-mile county. Its four primary waste treatment plants and 42 pumping stations now use the Web-based Simatic WinCC SCADA solution from Siemens Industry Inc. (www.usa.siemens.com/industry) headquartered in Alpharetta, Ga.
Although CCWS had previously considered upgrading its legacy SCADA software, management decided to shop around when it discovered that the new version of the old software did not offer a clean migration path and would cost the same as starting new. It chose the Web-based SCADA technology offered by Siemens because it alleviated some specific pain points that had been plaguing CCWS.
One was the high licensing costs that came with the old system. To give operators access to the data and HMIs throughout a plant, CCWS had installed more workstations than it had operators. One facility, for example, had eight licensed clients coming off its SCADA server, even though it had only three operators on site. Even though only three systems would be used at any one time, the facility licensed and ran all eight in order to give the operators access from these strategic locations.
“With a Web-based architecture, we are able to put Web licenses on the main server,” says Alan Cone, Siemens’ HMI product marketing manager. Instead of being assigned to the client computers, the licenses follow the operators, allowing them to log into the system wherever they are in the plant.
Because WinCC uses a structured query language (SQL) database, CCWS was able to import data from the old SCADA system using a flat file generated by conventional SQL tools. This allowed CCWS to transfer all of its historical information and improve the flow of information from the plants to the main office. Authorized users can see the entire infrastructure or drill down to the device level in any facility from any device that has an online portal using Web Navigator, says Bob Meads, president of iQuest Inc. (www.iquestcorp.com),the systems integrator in Alpharetta, Ga., that implemented the Siemens solution.
Another pain point alleviated by the new architecture is the ability to replicate objects and make global changes. Changing a pop-up screen for the old system, for example, required a programmer to go to every pop-up to make the alteration. Now that pop-ups are global, the programmer need only change one. Every identical screen updates automatically, which can reduce a four-hour job to just five minutes, according to Meads.
The evolution of standards has been one of the important advances in SCADA over the last few years, according to Philip Aubin, senior system architect for telemetry and remote SCADA solutions at Schneider Electric (www.schneider-electric.com)in Kanata, Ontario. “SCADA used to be a very niche and proprietary set of technologies,” he says. “There has been good agreement across vendors in the SCADA space on defining and adopting standards.”
These standards range from the typical information-technology standards for sending SCADA data to business applications to process data interchange standards like SQL, open database connectivity (ODPC), and open platform communications (OPC). For communication among assets that are widely distributed over several miles, standards include distributed network protocol 3 (DNP3) and IEC 60870-5.
For some, the adoption of industrial Ethernet extends to radios for communicating over long distances. “Industry has shifted towards utilizing Ethernet IP radios to provide communications to remote sites and is using fewer serial radios to do this job,” says Cimation’s Steve Stock, infrastructure systems engineer and supervisor at the Houston-based systems integration firm (www.cimation.com). “The robustness of the Ethernet radios makes it possible to incorporate new technologies into the SCADA network.”
Some of his clients are choosing to add remote video monitoring capabilities and embedding process control video images into their HMI graphics. “With remote video monitoring, operations can assess and evaluate the situation at a remote site prior to sending out an employee into an unknown situation,” says Stock.
Radios are often critical to the SCADA systems that California Polytechnic State University in San Luis Obispo has been specifying for irrigation districts supplying water to farms. In the western U.S. and abroad, these districts are quite large, and canals can be as long as 100 miles and carry 600 to 1,500 cubic feet per second. The university’s SCADA systems, predominantly from Schneider Electric, provide the necessary remote monitoring and control over the infrastructure to keep the water flowing and prevent flooding.
Rather than sitting in a control room, the operators of these systems are typically in the field, often driving hundreds of miles a day in their pickup trucks. To keep tabs on the system, they access the HMI with a laptop or handheld device just as if they were in a conventional control room. This real-time access allows them to observe any part of the system continuously, day or night, without having to physically go there and look. It also can track pump usage for preventive maintenance and monitor flow rates for legal disputes over water rights.
Although SCADA is not always part of every irrigation project, Cal Poly does specify it for all modernization projects involving PLCs. “Electronics eventually go bad,” explains Charles Burt, Ph.D., PE, chairman of the Irrigation Training and Research Center and a professor in the BioResource and Agricultural Engineering Dept. “So, I just don’t believe in automating things without being able to monitor them remotely and change target values.”
Three Success Factors
Burt notes that SCADA success depends on good upfront planning that requires attention to detail. “SCADA is just a tool, so it has to fit in an overall strategy,” he says. You need to ask basic questions, such as: Who is going to use this information, and who is going to maintain the equipment? “Once you have that thought out, you’re able to define what is needed.”
Detailing the specifics related to these questions is important for a complex system, especially when it involves hooking together pumps, gates, inclinometers, and other products from various vendors. For this reason, Burt recommends using a SCADA vendor that adheres to industry standards.
Teamwork is important, too. It has to begin by ensuring that all levels of management, engineers and operators are onboard and working on the same page. “If the operators feel that the technology is going to take over their job, it will fail,” says Burt. “Likewise, if the manager isn’t part of the team and doesn’t really know what is going on, the operators won’t get the support that they need.”
Burt also recommends putting together a team of outside contractors that will work together well to solve the problems that will inevitably rise, rather than pointing fingers at one another. “You know that there are going to be problems,” he explains. “So, it’s really a question of how you address them.” One way to foster cooperation is to define clear responsibilities up front. “When we write specifications, we try to be as clear as possible.”
For more information:
Honeywell Process Solutions www.honeywell.com/ps
Phoenix Contact www.phoenixcontact.com
Schneider Electric www.schneider-electric.com
Siemens Industry www.usa.siemens.com/industry
Vipond Controls www.vipondcontrols.ca