It used to take three or four people pouring over paper charts and digital readouts to determine whether or not the water levels were right at the waterworks at Pigeon Forge, Tenn. "It took us a lot more time and a lot more personnel to see what was going on," says Lynn Light, City of Pigeon Forge's water superintendent. The utility’s engineers installed a Rockwell automation system that has monitoring capability to allow Light to view the entire plant. "Now we can constantly monitor the plant from beginning to end. We can see if our system needs more or less water, and we can speed up or slow down the pumps based on demand."
The ability to monitor the entire plant from one location also gives Light better quality control and has decreased the cost of operating the plant. "We’ve seen a 510% reduction, and we can sit at a computer monitor and see every area of the plant. Before none of this was on computer." Light’s ability to view all functions of his plant from one location has dramatically changed his job. The result is gains in both efficiency and quality. Now five workers don’t need to scramble across the plant trying to scrounge up dataall that information is on Light’s monitor.
HMI Advances
Over the past three years, advances in HMI technology have affected every sector of discrete and process manufacturing, making both small and substantial impacts on software functionality and efficiency. New HMI products offer a high number of communication ports, as well as inherent gateways for the web enabling of nearly any device. Significant advances have included developments in wireless interfaces, as well as the availability of both larger and smaller panels depending on the user’s need. In addition, cost reductions in HMI products have made many of these advances affordable for manufacturers.
Developments in monitors and monitoring also allow companies to get a view of all manufacturing processes from either centralized or remote locations. Terminals are now enabled with advanced functions such as animation, trending, data logging and object math and logic expressions for added efficiency. The ability to diagnose problems remotely from the plant floor is emerging as another key operational advantage as well.
Advanced HMI technologies are now being paired with the more traditional HMI features, such SCADA, to create even more flexibility in their use and application. However, manufacturers have been slow to adopt and market these new tools.
It’s a Control Thing
Pigeon Forge’s new monitoring system was laid on top of its Rockwell legacy RSView 32, WebServer-based system. The new system includes centralized monitoring, which allows users to see all of the control data. "Say you want to look at temperature. It’s a control item. The system goes to that control and brings back that value," says Pradeep David, business manager, HMI and middleware products, Rockwell Automation. "As long as you can get on a web browser, you can see the entire plant from anywhere."
Not only can you see the plant from anywhere, but with new HMI developments, anyone can see it. Much of the system is now on open standards and can be viewed on a web browser in a Windows context. "Windows provides a nice user experience, which is becoming more important as computers become more prevalent among non-engineers and non-technical people," says Paul Shelton, HMI expert at Siemens AG of Munich.
Shelton also notes that the adoption of open standards has had a significant influence on HMI technology. "From my 16 years of HMI experience, the biggest change has been the move away from proprietary systems," says Shelton. "They made sense at the time, but the open-standard systems that followed since then are easier to use and cost less." Open standards also allow the ability to plug-and-play multiple applications.
Monitors Big and Small
Advances in flat panels are offering users both bigger screens for desktop and control room monitors, as well as smaller screens for systems installed in tighter spaces. "People are moving from the 12-in. to the bigger display to present more information," says Ann Ke, product marketing manager for panels and tablets at Wonderware, a subsidiary of Invensys, Foxboro, Mass. "They’re going to 15-in. Some are going to 19-in." Ke says that automation systems provide more information on plant operations now, and the larger flat panel screen allows operators to see more data at one time.
As mentioned, one concurrent trend is the increasing application of small screens. "Many firms are introducing smaller screens," says Jake Millette, an analyst at Venture Development Corp. (VDC, www.vdc-corp.com). "Smaller screens are more common in machinery and equipment where panel space is at a premium, while larger screens are more common for process controls."
With the trend toward larger and smaller screens, says Millette, the "The combined effect is that the share of medium-sized screens—1012 in.—is declining, as firms offer more large and small screens."
Advancing Wireless OIs
A recent VDC study projects that the North American market for wireless, on-site operator interface terminals will increase from $24.6 million in 2003 to $85.4 million in 2006.
According to VDC analyst, Jim Taylor, the largest markets for wireless operator interface terminals is in mobile programming, maintenance, and repair applications. "These enable people to monitor and interact with equipment without having to be in a fixed location," says Taylor. The VDC study also found that the most popular wireless on-site operator interface terminals are notebook computers, hand held computers, and PDAs.
Survey or no survey, not all vendors are convinced that wireless HMI is going to gain purchase among manufacturers. "A year ago, we thought wireless was going to be bigger," says Rockwell’s Pradeep David. "We do not see much demand for it and people are staying more with the regular computer. It may be cost, or it may be that wireless is fragile and not built for shop floor activity." Whatever the reason, David also suggests wireless will likely become more attractive as cell phone screens get larger in the next couple of years.
Some industry watchers note a resistance among manufacturers to most new HMI technology. "There is a slowness to take advantage of a lot of these new technologies and get over the fear factor," says Craig Resnick, analyst at ARC Advisory Group. "When you get down to users, they’re still using really old equipment. There is always a reluctance to change," says Resnick, "due to the culture of the factory floor—they’re geared toward evolution, not revolution."
Watching the Plant From Anywhere
If something goes wrong on the factory floor at Elk Corp.’s shingle plant in Dallas and it’s Sunday, the systems control manager knows immediately even though he’s relaxing at home. How? He’s monitoring plant operations via the picture-within-a-picture on his television screen while watching the football game. With new HMI technology, you just can’t leave work any longer.
Elk Corp. uses InTouch, an HMI product produced by Wonderware, a subsidiary of Invensys of Foxboro, Mass. "We have 10 local operator stations and we also run FactoryFocus which is view-only," says Paul Rogers, systems engineer at Elk Corp. "This allows our managers to view the manufacturing line while they’re in their offices or on the road."
Though plant managers can view plant operations remotely, they are not allowed to control the line from home. "Our managers can access the same visibility as the plant operators," says Rogers. "But we don’t allow them any control offsite. That’s a safety issue. You don’t want someone starting a motor remotely."
The value of putting HMI technology in front of managers offsite is that it allows them to view process difficulties without having to drive to the plant or rely on verbal descriptions. "The benefits come at 2 a.m. when you get a call from an operator who says âWe’re breaking off because of some tension spikes,’" Says Rogers. "The control systems manager can trouble-shoot from home without going into the plant."
Remote monitoring is aiding Elk Corp as it prepares to open a new plant in Tuscaloosa, Ala. A trainer goes to Alabama, and he can show Tuscaloosa managers how the Dallas plant runs by viewing it on the company VPN. "We can show them what the line looks when it’s complete," says Rogers. Once home, the trainer can view Tuscaloosa plant operations to make sure everything is running correctly.
The Wonderware system can also send messages to PDAs. "We purchased a bunch of BlackBerrys," says Rogers. "I wrote a SQL code for an event. If that event happens, it will page a certain individual." Rogers put a gas-leak detector near an area of the plant that uses hot oil. If there is more than an acceptable level of gas in the air, the control device sends an email to the system manager’s PDA. "That way he doesn’t have to go back to his room to get the message," says Rogers.
Handheld HMIs Keep Turbines Running Smoothly
By Steve Epperheimer
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C
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hugach Electric Association, the largest electricity provider in Alaska, is now using handhelds to quickly reference turbine data during the course of daily operations. Using Windows CE-based HP Jornada 450 handheld computers and Visual CE, a database development tool from SYWARE www.syware.com), the instrument group has developed a mobile application that provides full access to turbine data on a mobile platform. The new system allows for easy look up of information when there’s a turbine malfunction, or if management wants to know a specific parameter of a turbine or generator.
Handy Data Prevents Disaster
Electric plants are typically spread out over several acres, and surprise! It gets cold in Alaska. The new handheld data access approach is significantly more efficient than running back and forth to the instrument shop to look up information. It’s estimated that the new technology is saving each technician at least 30 min. per day. Sometimes emergencies occur and it is crucial for technicians to have turbine data at their fingertips. During a recent hydro-turbine startup, as the lube oil temperature began to rise, Chugach operators were able to use the new database to locate the digital I/O point on the programmable controller and make the necessary control point changes without having to rush back to the shop to refer to engineering drawings.
How it Works
The handheld runs multiple turbine databases that are mapped to corresponding Microsoft Access databases running on a desktop PC in the instrument shop. The "tag number," a unique number stamped on each turbine sensor and other key components, is used to reference drawings, calibrations, parts lists, trip points, specifications and technical notes. Lists of tag numbers and their related data are supplied by the turbine manufacturer, usually in Microsoft Excel or Access format. This information is used to build the Access database on the desktop, and then it’s synchronized to the Visual CE application on the handheld.
The main menu allows the user to select the plant. The next screen is used to select the turbine unit. After the turbine is selected, a form opens that allows access to the turbine’s database. This form is specific to the type of turbine, since each manufacturer uses a different tagging system. The user then specifies the tag number of the desired part in order to view associated data. The user can also search for a tag number by defining a filter using the field âDescription’ [contains] and then entering the service that the device performs.
In normal mode, all data is read only in order to protect it from being accidentally changed. An Edit button displays the form in edit mode, which has the same layout as normal mode, but with a few color changes to indicate that the user can now enter or modify data. Once the user adds/changes data as needed, they tap the Save button to return to the original read only form. Data collected in edit mode also can be readily synchronized to the desktop database.
One key advantage to this approach is the ability to easily modify forms to fit the company’s needs. For example, one of the gas turbine generators recently underwent a major upgrade. Upon completion, "loop checks"—a process for checking signals between different modules—had to be performed. The drag and drop user interface allowed the engineers to quickly re-design the database and forms associated with this particular turbine in order to list the drawings page and device points where the signals were terminated.
Prior to starting the retrofit, a new field was added to the database indicating which sheet contained the loop drawing out of approximately 100 sheets of engineering drawings. Having the sheet number easily available saved time compared to manually thumbing through the sheets to locate the drawing in question. Calibration specs for field instruments were also incorporated into the table, providing a faster reference for the calibration that was needed before the functional checkout of the upgraded unit.
Steve Epperheimer is an Instrument & Controls Technician for Chugach Electric Association in Alaska.
