Terminals connect people to processes with functionality, flexibility
In the 1955 movie, "The Ladykillers," Sir Alec Guinnes playing Professor Marcus, the leader of a gang of robbers posing as classical musicians, relates the line to his landlady Mrs. Wilberforce, played by Katie Johnson, "And didn't someone say, 'The eyes are the windows of the soul?'"I don't really know," answers Mrs.
In the 1955 movie, 'The Ladykillers,' Sir Alec Guinnes playing Professor Marcus, the leader of a gang of robbers posing as classical musicians, relates the line to his landlady Mrs. Wilberforce, played by Katie Johnson, 'And didn't someone say, 'The eyes are the windows of the soul?'
'I don't really know,' answers Mrs. Wilberforce, 'but, oh, it's such a charming thought, I do hope someone expressed it.'
Charming thought or not, when it comes to seeing the process as the 'soul,' users have certainly made the operator interface the 'eyes' of the process. According to the 'Operator Interface Terminals Product Focus Study' conducted by Control Engineering and Cahners Research, two thirds of users who specify, recommend, and/or buy operator interface (O/I) terminals do so for in-plant requirements. Of those, more than half use them in both continuous and batch manufacturing, 19% in continuous, and 8% in batch processing only. Discrete manufacturing seems to be playing catch-up in this area of automation technology with only 9% being used.
The preponderance of responses from process/batch users also mirrors the survey results when it came to picking the product features necessary for keeping O/I terminals alive in a hostile world. Although 20% of respondents listed non-rated terminals as their current requirements, a far greater number either had or wanted for future installation NEMA 4/4X-, 6P-, or 12-rated terminals. When matching environmental requirements to the job, it seems choices such as water tight (NEMA 4), corrosion resistant (NEMA 4X), submersible (NEMA 6P), and drip resistant (NEMA 12) certainly fit well into the dusty, dirty, drippy, corrosive, and wash-down world of process/ batch operations.
Many display features were high on the user wish list. Of all the features desired by the respondents, flat-panel packaging was at the top of the list, followed closely by touchscreen capability, readability at a distance, and readability in bright light conditions.
According to Mark Weiland, product manager, Rockwell Automation (Milwaukee, Wis.), 'Because of lower costs and proven reliability, flat-panel technology is now a very popular choice for operator-interface screens. Some reasons for this include increased performance, solid-state reliability, improved readability, and size. Flat-panel performance has moved beyond CRT performance, with a 50,000-hr half-life for flat panels versus a 25,000-hr half-life for CRTs. 'Additionally, unlike CRTs, their solid-state reliability, space-premium friendly size, lightweight, and readability means customers have the flexibility to use flat panels in virtually any environment, including outdoors. Advances in high light panel output have opened up new uses in outdoor and bright-light factory applications. Advances in active-matrix displays have greatly improved viewing angles. And because they are lightweight, they're a good choice for pendant-type station configurations,' Mr. Weiland adds.
When compared to conventional CRTs, flat-panel screens also have the advantage of using less panel depth for a given screen size. However, thicknesses do vary. Depending on the electronic packaging of the unit, they can vary greatly anywhere from around 50 to 150 mm. Even in the smaller packages, availability of features has increased. According to Jon Giardina, group product manager for Omron Electronics (Schaumburg, Ill.), 'Omron sees I/O touchscreen capability moving toward functions traditionally performed by HMI/SCADA packages (trending, logging data on a time-driven basis, more flexible and powerful screen objects, etc.).'
Additionally, the fact that the cost of flat-panel technology is now only three times greater than an equivalent CRT at the retail level and rapidly falling, cost parity between the technologies is very near... 'Just around the corner,' Mr. Giardina says.
Bob Honor, manager of control and OI at GE Fanuc Automation (Charlottesville, Va.), sees flat-panel touchscreens as functionally outperforming standard hardwired control panels at a cost ratio of at least 2:1. According to Mr. Honor, a $500, 5-in. touchscreen/software package can easily replace the functions of a 10- to 20-device control panel consisting of pushbuttons, pilot lights, selector switches, terminals, wiring, etc., that with labor and installation can cost $1,000 or more.
Getting the point
On average, survey respondents have 1,356 tags for an operator interface terminal. The number of I/O points or tags per terminal is not necessarily indicative of the type of industry that the terminal is serving. Seventy-six percent of the respondents have need for only 500 or fewer tags in their system. Twenty-two percent license from 500 to 10,000 tags. The remaining 3% specify 10,000 tag references per unit.
Process operations can vary in size from a sprawling petrochemical plant to a tiny mixing/blending operation. Likewise, discrete operations span a wide range-a single CNC machine to a vast vehicle assembly line. The number of tags per terminal can be more a function of how much useable information can be handled by an operator on a single unit than total number of software inputs/outputs needed for overall operation.
Keeping the process in plain sight of the operator is certainly what O/I terminals are about. The technology has evolved to the point where the connection between humans and machines can now be conveniently placed at any point in the process, where access to control and process data are required. What a (charming?) thought, a convenient, flexible, and functional way to 'see' into the process.
Operator interface products
An expanded version of this Product Focus article with additional product descriptions is available at www.controleng.com . For more information on these products, circle the following numbers, or visit www.controleng.com/freeinfo . For a wider listing of manufacturers, go to Control Engineering Buyer's Guide at www.controleng.com/buyersguide .
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Xycom Automation Inc.
ABB Process Automation
GE Fanuc Automation
Eaton Corp., Cutler-Hammer
Axiom Technology Inc.
HMI increases mobility
Milwaukee, Wis.- MobileView family of portable human-machine interface devices allows personnel to move around a machine, down a production line, or throughout an entire plant when using an interface, which is said to result in greater worker and plant productivity. The thin-client technology-based interface allows manufacturers to have information and machine control wherever required. MobileView also provides lower total cost of ownership, since maintenance and repair is more efficient and cost-effective. www.ab.rockwell.com Rockwell Automation
Slim bezel terminals
Cumming, Ga.- AutomationDirect.com will offer two slim-bezel models of its EZTouch line of operator touch panels, starting in January 2002. The panels available in slim bezel versions include both a 6-in. monochrome and a 6-in. color full-feature model. EZTouch operator panels feature serial connection to many brands of PLCs, including Allen-Bradley, GE Fanuc, and AutomationDirect PLCs. These slim bezel panels will be priced at $429 for the mono version and $829 for the color version. www.automationdirect.com AutomationDirect.com
I/O has connectivity options
Schaumburg, Ill.- Omron's new NT631/NT31 series monochrome, electroluminescent, and color operator interface touchscreens can communicate with Allen-Bradley SLC 500 and GE Fanuc 90-20/90-30 PLCs. New software provides capability to download these vendors' protocols to the touchscreens. The O/I's slim 1.8-in. depth complements the large 11.3-in. color screen of the NT631, while a 32-bit RISC processor ensures smooth operation. A portable flash memory module is said to eliminate the need for a PC when updating a remote site or downloading screen data to multiple touchscreen units. This memory module has two 1MB banks, each capable of storing the screen data from a fully loaded NT. The new models provide improved connectivity with two serial ports and a printer port. Serial port B can be configured for PLC communications. Serial port A can connect to a PLC, accept screen data downloads from a PC or connect to a bar-code reader. www.omron.com Omron Electronics Inc.
Basic industrial PC
Alpharetta, Ga.- Simatic PC Industrial Lite family of computers is equipped to meet a number of performance standards for applications requiring an industrial-style form factor, moderate shock and vibration resistance, and electromagnetic-compatible shielding. In addition to having an integrated front operator panel, the Industrial Lite PCs resist vibration to 0.25 G, resist shock to 1 G, and can operate at ambient temperatures up to 113 °F. Two display options include a 12.1-in. (800 x 600 pixel) and 15.1-in. (1,024 x 768 pixel) screen. Both are available in touchscreen versions. The PC can be ordered with a choice of operating systems, including Microsoft Windows NT4.0 and 2000 Professional; and main memory sizes (128 MB to 256 MB). www.sea.siemens.com Siemens Energy & Automation