Graphic operator interfaces improve communications with machine operators by providing a visual representation of what is taking place in the PLC or controller. Because of the expanded communications power of graphics, graphic touchscreens are one of the most popular operator interface choices for industrial automation; however, an operator interface rich in communications-enhancing graphics may cost thousands of dollars, making it one of the most expensive components of many systems.
Many engineers and systems integrators, especially small machine designers, find that graphic operator interface terminals—also known as human-machine interfaces (HMIs)—won't fit their systems' requirements in two major aspects: size and cost. Most graphic touchscreen displays are at least 5-in. diagonally, and the high cost of the technology can be prohibitive. This forces many engineers and systems integrators to forgo the impressive communications power of graphics for smaller, lower-priced text displays with limited communications abilities.
Space- and cost-saving solutions
Maple Systems, a provider of operator interface products, has developed a new line of graphic operator interfaces called the Blue Series, which provide high-quality solutions that address the issues of size and cost. Made with a 3-in., 128 x 64 pixel graphic display, the Blue Series has measurements that will fit into smaller systems but will work equally well in larger machines. Its dimensions are just 5.8-in. x 3.8-in. x 1.6-in. The display is a monochrome STN LCD with backlight that displays both graphics and TrueType font text. Graphics are available in pre-existing libraries, or they can be created in other drawing programs (such as AutoCAD) and imported as 8-bit bitmaps.
These graphics tools allow engineers to facilitate improved HMI communications through the display of graphic objects such as meters, bar graphs, lamps and other 16 or 32-bit PLC register control. For instance, conditions occurring in the PLC can be displayed on the HMI as a panel meter. This feature can be configured in 300 or 360 formats with adjustable minimum/maximum ranges and scaled with major and minor tick marks, giving the operator a clear, easily interpreted visual representation of PLC conditions at any given time.
Data entry is achieved through user-defined function keys that can be programmed to be screen-dependent. Five data entry keys are available, and the number can be doubled with the "Shift" key. Keys can be configured as latched button, jog button, momentary on/off switch, set constant, set password, push on/off switch, numeric input and screen jump. There are also arrow keys for numeric input and "Esc" and "Enter" keys.
Function keys and numeric entry objects can be assigned one of 10 security levels to protect critical processes. The PLC can activate the HMI's alarm LCD and alarm buzzer, as well as control which screen is displayed.
The Blue Series has up to 999 programmable screens available, with a user-definable startup screen. It also has optional compact flash for easy program uploads and downloads, and a real-time clock that helps preserve PLC resources.
The Blue Series supports both RS-232 and RS-422 communications, and communications protocols are available for many of the major PLC and controller brands, including protocols for Allen-Bradley, GE Fanuc, Siemens and Modbus, as well as available protocols for other manufacturers of PLCs and motion controllers.
The Blue Series operator interfaces are available for less than $200.
More Graphic Solutions
If size is not an issue but cost is, Maple Systems offers the Silver Series line of affordable graphic touchscreens. Pricing for the Silver Series starts under $500 for graphic touchscreen operator interface terminals featuring up to 256 colors, graphics libraries, importable bitmaps, and three types of animation. Hardware features of the Silver Series include 10BaseT Ethernet, compact flash port for data uploads and downloads, real-time clock and high-resolution touchscreens. These HMIs also have programming features such as macros for running scripts in the HMI, non-volatile recipe storage that stores up to 32,767 recipe items, tag database for easy program conversion, online simulation that allows engineers to test their program before loading it to the HMI, and multiple language labeling for changing the language of the HMI labels with the push of a button. The Silver Series HMIs come in 6-in., 8-in. and 10-in. displays in a variety of configurations and options.
Product and technical information, demo software, technical notes, and informative articles are available at Maple Systems' Web site: www.maple-systems.com .
Click logo to download demo software for the Blue Series.
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Everett, WA 98532
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