Operator Interfaces Shrink, Expand, and Web-Connect

Exciting new technologies are making larger flat-panel displays with sharper images possible. The first products with technology derived from the web (the world wide web or Internet) are appearing. The popularity of micro PLCs has opened a market for small operator interface devices while technology is giving them a new, improved look.

By Gary A. Mintchell, CONTROL ENGINEERING April 1, 1998
  • Human-machine interface

  • Machine control

  • Data display devices

  • Graphic displays or terminals

  • Operator interface

  • Touchscreens

Welcome to the real-time manufacturing era

Exciting new technologies are making larger flat-panel displays with sharper images possible. The first products with technology derived from the web (the world wide web or Internet) are appearing. The popularity of micro PLCs has opened a market for small operator interface devices while technology is giving them a new, improved look.

Advances in software and operating systems will drive how operator interfaces of the future are used (see the sidebar by Michael Goeke on how object oriented programming is changing control programming).

Like the chart shows, companies are looking for ways to integrate technologies in hardware and software to make a consistent interface across an entire range of a product family.

What’s coming?

Jim Thorpe, operator interface product line manager for Cutler-Hammer/Eaton (Westerville, O.), says, “Flat-panel display technology is advancing rapidly. Flat panels have better reliability than CRTs and are catching up in such important areas as resolution, clarity, and viewing angle. They also take up less space.”

Mr. Thorpe also sees a movement toward open platforms with connectivity to the various networks found in manufacturing as essential. Operating systems embedded into a chip will allow manufacturers to place much more functionality in ever smaller devices.

Robert Mick, software engineering vice president at NemaSoft Inc. (Ann Arbor, Mich.), sees further benefits derived from web technology. “Hand-held technology will enable significant cost reductions in smaller Operator Interface devices. Web technology is being integrated into a wide range of consumer products from the Microsoft Palm PC and 3Com Palm Pilot to network computers. Factory-floor systems benefit tremendously from the open architecture and portability which is the key to a web system.”

Two examples of web technology are now real products.

Ann Arbor Technologies (Ann Arbor, Mich.) has the WebLink. This factory-floor network computer has a Sun Sparc IIep processor, Java operating system, and a 13.8-in. active matrix TFT (thin film transistor) display.

Dynapro (Delta, British Columbia, Canada) is offering a diskless PC with Microsoft Windows CE embedded. The active matrix TFT flat panel display comes with a resistive touchscreen or an optional patented Near Field Imaging touchscreen.

Joe Zons, Rockwell Software (Mayfield Heights, O.) application engineering manager, MMI, sees customers looking for the ability to share information from the lowest to the highest level in the company in a consistent format. This will push the emergence of Windows CE which will allow a small, inexpensive device to look like a Microsoft Windows 95 or NT display. He goes on to say, “The ability for the operator interface to effectively interoperate with a customer’s MES/MRP/ERP systems will be more and more prevalent throughout the industries.”

Networks, graphics

Dennis Waldenmayer, Xycom’s (Saline, Mich.) business manager for industrial computer products, sees the advantages of full personal computers as their ability to easily network and extend graphic capabilities. Using Windows CE allows use of the Windows environment while holding down costs because less memory, mass storage, and processor performance are required.

Watching the operating system offerings from Microsoft, the possibility of making similar looking operator interfaces ranging from small devices (using Windows CE) to large networked systems (using Windows NT) now is likely. (See graphic adapted from Rockwell Software, West Allis, Wis.)

Reflecting this vision, Rockwell Automation/Allen-Bradley (Milwaukee, Wis.) now has color flat-panel displays from 6- to 15-in. and a 20-in. CRT monitor which all use a common software configuration.

Cutler-Hammer/Eaton is developing a line of operator interface products to enhance the PanelMate series and provide a consistent interface. Just-introduced, PanelMate PC 7000 series bundles the soft operator interface with a PC into a single workstation. Fully compatible with the PanelMate Power series, the PC 7000 comes configured, tested, and ready to run. The product utilizes DDE (dynamic data exchange) and DLLs (dynamic link libraries) to enhance communication with Microsoft Windows applications and is compatible with PLCs from all major manufacturers.

Richard Galera, Schneider Automation (North Andover, Mass.) HMI marketing manager, sees human-machine interface (HMI) becoming the central position in the automation business. Dynamics such as the integration of software—from control through operator interface to management systems and advancements in information technology like web browsers with internet/intranets—are driven by PC technology from the consumer market becoming more feature rich at a lower cost.

Schneider Automation is extending the Magellis line of operator interface into a family of products from small text displays to PC-based software packages for networked applications.

With the popularity of microcontrollers, demand for smaller, more economical OIs increases. Leveraging some of the technology and graphic knowledge from larger PC-based interfaces, manufacturers have introduced a wealth of small devices from hand-held interfaces to graphical flat-panel displays in the 5.5- to 10-in. range. Some of these smaller devices now even have color capability.

Hand-held devices

Hand-held devices now being introduced are increasingly from third-party manufacturers rather than proprietary devices supplied by the PLC manufacturers. Open competition for the hand-held market is not the only thing to watch. Look at the technology used by the local UPS or Federal Express driver. Don’t be surprised to see Windows CE or Java systems similarly embedded in the small devices for the factory floor of the not-so-distant future.

John Browett, product marketing engineer at Mitsubishi Electric Automation Inc. (Vernon Hills, Ill.) says, “As the microPLC’s power and functionality increases, low-cost OIs such as our E200 are also showing greater enhancements. Features such as alarm handling, real-time clocks, and serial communication ports are now offered without a significant increase in price. Software has been instrumental in maximizing the capabilities of a basic hardware platform without adding significant cost.”

Two Technologies Inc. (Horsham, Pa.) now offers the HV-30 hand-held terminal. This ASCII terminal with serial connectivity (RS-232, 422) has a 2-line by 40-character LCD device. Supertwist LCD and backlit LCD are also available. The 30-key membrane keypad has configurable function keys. Priced at just over $200, this is an economical entry-level system.

Adding an interesting feature to hand-held operator interface, Euchner-USA (Hibernia, N.J.) offers the Lauer TSN 100 PLC modem. This operator interface is designed for the service technician who may be in a different location from the control. One TSN 100 is connected to the PLC at the machine. The technician carries another. When called upon to troubleshoot the machine or download new programs, the technician plugs into the phone service, calls the other modem, and performs the necessary work. TSN 100 also will connect into the Lauer PCS Operator Panel.

TD17 text display from Siemens Energy and Automation (Alpharetta, Ga.) is an LCD text only display that can use two font sizes. The 6- and 11-mm fonts can be mixed on one line or use only one for emphasis or to pack more information on the screen. TD17 is programmed with the current Pro Tool software operating under Windows 95. It has drivers not only for Siemen’s Simatic products but also for several other brands of PLCs.

PLCDirect’s (Cumming, Ga.) OptiMate family of operator interfaces are low-cost LCD interfaces that feature user-configurable function keys, annunciator lamps in various colors, and setpoint display capability.

Color adds impact

Forces driving color down to the small displays are not just for a pretty picture. Chris Meunch, Siemens Energy & Automation applications specialist, points out, “Usability studies have proven that a color display and an ergonomic way of choosing colors like gray and pastel green for good states, and red, yellow, or any other aggressive color for bad states reduced the failure times of plants. The operators were able to recognize failure states faster with more accuracy.” He also sees the web interface style dominating the way operator interfaces will display data in the future.

Aromat Corp. (New Providence, N.J.) has incorporated two-color backlit LCDs into the D30 graphic touch panel. Paging functions create screen changes such as a flashing red light alarm. The D30 can display text, graphics, symbols, and bar charts. The product stores up to 256 message screens with up to 32 function keys per screen.

GE Fanuc Automation (Charlottesville, Va.) builds in networking to each display station in its Cimplicity HMI product line. On the low end, the Datapanel 160 still supports graphics, messaging, alarming, scaling of data, redefinable function keys, and membrane keypad data entry. Fieldbus networks such as Profibus and Genius are also supported. The Datapanel 1000 series has ported color active matrix TFT down to a 10.4-in. display. Engineers at GE Fanuc believe Windows CE will add more functionality to low-end devices while the market will also drive manufacturers to larger flat-panel displays.

Larger and sharper

Larger flat-panel displays made for the factory floor are beginning to make it to the market. Total Control Products (Melrose Park, Ill.) has introduced the Marathon Series of PCs, monitors, and peripherals. The monitors have TFT color technology with SVGA (800 x 600 pixels) and XGA (1,024 x 768 pixels) resolution. The displays are up to 14.9-in. active matrix TFT and 17.7-in. passive LCD.

Many times the lack of a proper software driver renders a new display useless. Christensen Display Products (Seattle, Wa.) has introduced a line of flat-panel displays designed to work with a wide variety of video cards and drivers.

“Most of the time the user can just plug in the display, make a couple of hardware adjustments, and use,” according to vice president Rick Tomfohrde.

Sometimes the resolution of the graphic presented to the monitor is not of sufficient quality for higher resolution screens. Interlaced full motion, video and progressively scanned computer graphics are a challenge. Computer Dynamics (Greenville, S.C.) has developed the Vamp-SmartSize. Available in Computer Dynamics’ panels from 6.4- to 15-in., the Vamp-SmartSize provides smooth image resizing so that VGA images will now fill the entire SVGA or XGA screen. Video from NTSC video sources like CCD cameras, VCRs, or any type of TV signal can be displayed. Automatic calibration makes it easier to get the optimum image on the screen.

If a 15-in. display isn’t large enough for graphics, Aydin Displays (Horsham, Pa.) has the answer. The AMLCD FPD is a 20-in. active matrix LCD flat-panel display that supports 1,280 x 1,024 pixel resolution.

Touchscreen versatility

Touchscreens on displays give designers the ability to program color pushbuttons and function keys that appear on the screen. This frees the operator from looking at the screen and searching for the appropriate function key.

Combining the trend toward larger flat panel displays with their expertise in touch, Elo Touchsystems (Fremont, Calif.) is now shipping two new flat-panel, active matrix, TFT displays. The Trimline 12.1-in. Touchmonitor features the Elo AccuTouch five-wire resistive touchscreen while the 14-in. model has a surface acoustic wave touchscreen in a NEMA 12 configuration. The 12.1-in. model has SVGA resolution and the 14-in. one is XGA.

Inova Inc. (Richland, Wa.) has taken surface acoustic wave technology a little further and claims to have the first packaged in a NEMA 4X display. The 12.1-in. active matrix, TFT display has 4,096 x 4,096 individual touch points so that ultra-fine precision is achieved. Have a problem with a glob of grease or peanut butter from lunch stuck on the screen giving a false signal? Inova engineers have developed algorithms that “see” an unmoving object and tunes it out.

Users like color, functions

Helm Instrument Co. (Maumee, O.) manufactures press control automation systems using Allen-Bradley color Panelview 600 for the operator interface. Vice president Mary Tice says that operators love the color displays that consolidate several different operator interface devices into one unit. An added benefit is that faults are displayed in English. Set up and troubleshooting become much faster, increasing the customer’s production.

Finally, in what may be the shape of things to come, Fujitsu Microelectronics (San Jose, Calif.) has released the ImageSite 42, a 42-in. flat-panel plasma display. This large display is not ready for the factory floor although there are plans to do just that eventually, but just think of the plant layout possible on screen with this much available real estate.

Welcome to the real-time manufacturing era

New object technologies such as OLE for Process Control (OPC) and the Distributed Component Object Model (DCOM) are allowing industrial applications to become more finely distributed while remaining integrated by way of system architecture. Distributed data within an integrating architecture fit the distributed nature of the intelligent plant-floor and the access needs of the overlying business systems.

The impact of these object technologies will be significant. Some observers had projected that “componentization” would allow many different suppliers to independently provide functional objects within the industrial system. In industrial applications, object technologies will reduce the suppliers’ cost of developing applications, the implementers’ cost of integrating applications and the owner’s costs of training and maintenance.

The OPC initiative holds promise for deploying OLE into the industrial environment. Where an OPC server and client are available, applications will be able to interact at the data-level using tag and attribute names. This “standardized” inter-process communication uses the full set of Microsoft object-based technologies. Integration can be tighter and more agile with lower custom software content.

The Distributed Component Object Model provides for the fine distribution of objects by allowing objects to “live” at distributed locations on a network and be referenced consistently from anywhere. On the screen, it may appear that data are within the computer on which the application is running. In reality, data are distributed across a number of intelligent devices on the network.

These two technologies, OPC and DCOM, are complementary and will result in eliminating the proprietary drivers used to connect data from the device to the application and from application to application. For industrial applications at and above the HMI level in the architecture, these techniques will see wide acceptance. The Manufacturing Execution System (MES) layer where integration costs have remained high will see an immediate benefit from these techniques. Current MES projects with integration service content over 40% will see drastic improvement as “drag and drop” integration is provided within the base technology.

In the real-time layer, interlocking between real-time controllers and PLCs is expected to remain proprietary for some time. Control requirements for deterministic performance, speed, and robustness must be fully satisfied before wide-spread usage can occur. The overhead and resource requirements for these techniques place them outside of immediate consideration for many control applications. As the hardware speed-to-cost ratio continues to improve, these technologies will be accepted at the control level also.

The OPC and DCOM impact in industrial automation will be further amplified when combined with other supporting technologies such as ActiveX, Ethernet, HTML and dynamic HTML, micro web servers and browsers. In combination, the result will be a flurry of new products as these new technologies are adopted.

The information requirements imposed by integrated ERP systems and supply chain automation systems can finally be satisfied with this set of technologies. Integration of the large, data-creating machine called the plant-floor with the slower business processes has always been the dream of automation. The technologies have caught up. The era of real-time manufacturing is starting.