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| Common Sense And
The Year 2000 Problem In Automation Systems
By Robert F. Weir, P. E. What’s The Problem? You have probably read or heard about the Year 2000 problem. What you may not have heard is what the problem really is about. In order to think rationally about this issue and its consequences for your business, it’s important to have some facts: The Year 2000 problem is associated with the ability (or inability) of computers to properly compute year dates. Because of this inability, some computer programs may not recognize the year 2000. The problem is not limited to any one programming language or computer application. It is true that very old software applications written in COBOL language, because of the primitive date handling routines characteristic of that language, may have a more serious problem. But those applications are by no means the only ones at risk. In order to have a Year 2000 problem, a computer system must be capable of computing dates. If a system is not designed to compute year dates, it cannot have any essential functions which involve the use of those dates. Therefore, there is no Year 2000 problem with that system. It is difficult, however, to know whether or not individual systems are capable of computing dates without some investigation. Take Action Now For most computer equipment, there are several pieces of software needed to perform useful tasks, whether they are data processing, word processing, or machinery control applications. All of these individual pieces of software need to be checked for the existence of essential calendar operations and for proper function of those operations with year 2000 dates. Finally, there has been a good deal of comment that seems to ascribe an almost metaphysical quality to the Year 2000 problem. There is nothing mysterious or inevitable about a computer-related programming glitch. Once you understand the problem, an organized plan and decisive preventive action is very effective in minimizing or avoiding the consequences. On the other hand, a lack of knowledge and inaction can be very costly. PLC Control Systems Computer systems which control machines and processes present a somewhat different problem than other kinds of computers. In these systems, the product of the calculations performed is the electronic manipulation of electric control switches and signals which cause machinery and processes to operate automatically. These systems fall within the broad category of automation controls, and they are generally of two kinds. First, and perhaps most numerous, is the programmable logic controller (PLC), a general purpose automation product available since the 1970s. Second is the more specialized control originally used for machine tool automation, the computer numerical control (CNC). PLC technology has developed to the point where nearly all makes and models incorporate some clock/calendar capability. This is a fairly recent development in the history of these devices, a fact which has two fortunate consequences: (1) older installations do not usually have date capability; and (2) units which have date capability are usually capable of handling Year 2000 dates. At this writing, many manufacturers have stated that they have completed testing of their products for Year 2000 readiness. Specific information can be obtained from the manufacturer of the unit in question. Don’t Forget To Check Application Software With any PLC control, remember that the software furnished by the manufacturer is only part of the potential problem. In order to use a PLC in an automation project, it is necessary to program it to control the equipment to which it will be connected and which it will control. This "application" program is yet another piece of the puzzle of finding potential problems with Year 2000. Since application programs are unique, information from the manufacturer is not helpful in learning whether the application is capable of handling Year 2000 dates. It is essential in PLC applications having a clock/calendar that each application be subjected to actual testing by setting the clock ahead to 23:59 of 12/31/99 and observing the rollover. Because an application programmer might have contrived a synthetic clock calendar of his/her own, it is advisable to subject all PLC applications to this test.
CNC Control Systems CNC control is a specialized type of automation device applied to a machine which must move tooling through a precise path. That enables the machine to produce a part by cutting, grinding, or forming material. Individual programs are associated with the part they produce. It’s also unusual for these machines to have a use for date information. CNC units with date computation capability, therefore, are a fairly recent development. As with PLC controls, the more recent development of CNC controls make it more likely that they can process dates correctly. However, you could contact your respective equipment manufacturers for specific information. What Can You Do? There is one hard and fast rule applicable to Year 2000 preparation — a positive result requires organized and effective action. To the extent that there are year date handling problems in systems which might affect your business, they will cause some disruption unless you act now to locate and correct them. The following action steps are a minimal approach to this problem. In most cases they will be effective. If it appears that other action is required, by all means include it in your plans. But get started now, if you have not already. Inventory Make a list of automated equipment and processes important to your business or operations. Consult drawings, maintenance records, purchasing records, or physically sight each device. Record the name of the manufacturer, model number, and other identifying information for each digital computer-based device and list each one separately. Prioritize Arrange the inventory list in order of decreasing significance to your business operations. Do not assign priorities lightly. Take the time to understand the potential effects of a malfunction of each item. Gather Information Consult the manufacturer of each device in order of priority. Ask specifically whether the device:
Depending on the answers to these questions, make specific action plans to take necessary action. Test Key Systems Regardless of information developed from manufacturers or from other sources, it is wise to test important systems as far in advance of 12/31/99 as possible. Not only will the existence of Year 2000 incompatibilities be revealed, important knowledge about the capability of vital systems and machinery will be gained. Such knowledge is the real key to facing the new millennium with confidence that major upsets to the business are not likely to come from the Year 2000 problem. When preparing your test, be sure the equipment is placed in the mode least likely to result in permanent damage should a Year 2000 date problem occur. In especially sensitive applications, it may be justifiable to purchase duplicate electronics. Load them with a copy of the application program in question and run them "on the bench" (not connected to actual equipment). The test should include the following items as a minimum:
In all cases, the manufacturer of the equipment in question is the first and best authority on how testing should proceed. If a "systems integrator" was involved in assembling or programming a system, consult him or her as well. Also confer with the applications programmer, when available. Corrective Action Where corrective action is indicated, by all means take that action. If an offending system or component can be replaced with a trouble-free equivalent, that option should be carefully evaluated. It can be less costly in the long run. Test Again If corrective action has been required to a system or machine, do not neglect to repeat the testing step. It is the only sure way to know that the problem has been overcome. Staying On Track There will always be conjecture or "what if" scenarios offered in connection with Year 2000. For example, a colleague may relate hearing a prediction that "all telephone switches have a calendar chip which is not Year 2000 compliant." Deal with such matters rationally by asking for some technical facts. Ask questions. Who are the manufacturers? Is there is a calendar capability in the device? Has anyone asked the manufacturer about the problem? If there is a calendar present, what happens if it cannot process a Year 2000 date? By demanding technical rigor, you will quickly learn whether there is a real problem to be addressed. If so, simply place the matter in the priority list described above and handle accordingly. Robert Weir joined Hartford Steam Boiler in 1993 and was appointed Director in 1995. He has an extensive background in the design and construction of power generation and industrial equipment and systems. A graduate of the U.S. Naval Academy, he holds a Master’s Degree in mechanical engineering from Worcester Polytechnic Institute and is a graduate of Suffolk University Law School. He is a member of the American Society of Mechanical Engineers (ASME), a permanent committee member of the National Fire Protection Association (NFPA 37), and is admitted to Massachusetts and federal courts, including the U.S. Supreme Court. Appendix A Year 2000 Progress Chart To aid in this process, you may find the following progress chart to be useful. It is given as an example, and you can expand or modify the chart to meet your individual needs.
Web Sites Of Interest [Note: These product sites are presented for information only. Hartford Steam Boiler does not endorse any of these companies or their products. The author has provided an over view of many of the companies in the market, but this should not be construed as a complete or comprehensive list of manufacturers and products.] Rockwell Automation/Allen Bradley Honeywell Johnson Controls Foxboro Company GE Fanuc Automation GE Information Systems Square D Groupe Schneider/Modicon/Telemechanique/Merlin Intellution Wonderware |
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