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THE WAY I SEE IT By NEVILLE WILLIAMS Electronic identification: a boon or a catastrophe? If the proponents of electronic or RF identification are to be believed, it could turn out to be revolutionary. Applications currently being discussed range from freight wagons, road vehicles and containers to living creatures - including human beings! As you may recall, the subject of electronic identification was raised last month by a reader who drew attention to an article in "Farm" magazine which described a subminiature electronic identification device. Especially applicable to animal breeding stock, it is being distributed - and used in their own stud - by an Adelaide-based company: AGTEC Australia Pty Ltd. Essentially a tiny integrated circuit chip in a 10mm-long plastic capsule, it can be implanted under the hide of an animal, with minimal pain and disfigurement, using a special hand-held syringe. During manufacture, each capsule is encoded with a different number, which can be read electronically with the aid of a suitable interrogator. By referring the encoded number to a data bank, the identity of the animal can be checked, along with other relevant information. The reader in question (P.D. of Murchison, Vic) was intrigued by the article in "Farm" magazine but was also disturbed by it. His reasoning: if we develop a high level of expertise in electronically tagging animals, who is to say that the next step won't be to tag people? 86 SILICON CHIP As I write, the October issue carrying the arlicle has not yet reached the newsagents and I have no way of knowing if other readers will share P.D's apprehension; or if they do, how many will put pen to paper. Another approach In the meantime, I came across an article in the computer section of the "Sydney Morning Herald" (August 14th, 1989} detailing another ID/information system. This is currently being put in place at Harry M. Miller's SimmentalHereford Dunmore stud at Manilla, NSW. It rates a mention here, if only because it illustrates a different approach to that adopted by AGTEC. At Dunmore, they are still using ordinary ear tags to identify individual animals but are concentrating instead on the development of a comprehensive on-site computer data bank. This is based on a program called "Ag-Vantage", developed by Alan Morgan of Far South Coast Computer Specialists, Bega, NSW (phone 064 923 066}. According to the article, reaction to the system by the management at Dunmore is nothing if not enthusiastic. I quote: "We have been using AgVantage for about 2½ years and it has saved us more time, given us better results, earned us more money than you would believe. With it, we have a complete history of each animal. We know which are the good producers, which are not; which are earning their keep, which are on the bludge". The next step at Dunmore is to install automatic electronic weighing as the animals pass through a race, with provision to feed the information into the data bank. Together, the AGTEC and Dunmore stories provide a practical illustration of what's said to be ahead for Australia's huge livestock industry: electronic tagging of individual animals and computerbased information storage, management, handling and marketing. That could add up to a lot of equipment. Outback electronics As an urban dweller, you may find all this a bit of a yawn; something the "cockies" are up to, out beyond the black stump. If they want to mess about with ID or AID (animal ID) or EID (electronic ID) or RF ID (radio frequency ID}, so be it - as long as they keep on sending us meat to eat and horses to race! In that case, you might be interested in a totally different story from the Barrier Reef, featured recently in the TV show "Beyond 2000". For years, crown of thorns starfish have been gnawing away at the coral, while frustrating attempts to document their migratory habits. They dispose of ordinary tags by shedding the arm to which they're attached and growing a new one! But researchers appear to have come up with an effective answer. You've guessed it: a tiny integrated circuit in a 10mm-long plastic capsule which is injected into the crown of thorns' body by means of a hand-held syringe - both items remarkably like those in last month's AGTEC story. Not surprisingly, the underwater interrogator is different and uses a loop which is lowered over the starfish. But the result is the same. A low frequency radio signal energises the chip in the capsule which obliges with its own unique number - in the case of the "Beyond 2000" story: 7F7E3F4565. Still not convinced? Well, what about the nationwide TV interview, in the same week, with an American judge who's been promoting the use of RF ID devices to keep track of plain, ordinary human beings? Sentenced to home detention rather than prison, they are fitted with an electronic ankle bracelet which sounds an alarm at the control centre if the detainee ventures beyond the allotted boundary'. I concede that home detention may be preferable to a prison cell and less of a burden on the public purse. But the interview wasn't limited to lawbreakers; the conversation turned quite casually to other possible uses for the device - like keeping track of. the aged and menta:lly handicapped. It was all about the capability of the equipment with not one word about the broader implications of attaching it to humans who are socially somewhat inconvenient. Ankle straps today; implants tomorrow? ID - the broad background Last month, I mentioned papers made available to me by two departments at the University of New England, Armidale, NSW: the AGBU (Animal Genetic & Breeding Unit) headed up by Dr Keith Hammond, and the CEA (Centre of Electronics in Agriculture) which is headed by Dr Royden Lake. INTERROGATE/RECEIVE ANTENNA '-....,_ SENSING/TRANSMIT ANTENNA "cT/ 'f'I rI - - - - INTERROGATOR (AXED OR PORTABLE) f POSSIBLE DATA LINE I / I II ~- {~ \ POSSIBLE OPTICAL TRIGGER J 13-~ POSSIBLE OPTICAL RECEPTOR POSSIBLE TRIGGER/ SUPPLY SIGNAL Fig.1: concept diagram for an electronic ID system. The interrogator sends an RF interrogation signal, plus a possible second RF signal to power the transponder. Some systems use an optical activating signal. The return signal is intercepted and displayed by the interrogator. In fixed installations, the interrogator may be linked to the central computer data bank. By way of background, one such paper points out that RF ID dates back to at least the 1960s, when it was adopted as a way to keep track of railway freight wagons, particularly in marshalling yards or when crossing state or national borders. Readers with still longer memories may recall wartime IFF (Identification Friend/Foe) units, which enabled night fighter planes to interrogate other aircraft before launching an attack. Of necessity, early interrogators and transponders used valve based circuitry, limited in its usefulness by bulk, power needs, complexity and cost. The amount of data which c9uld be exchanged was also very small. One early system, for example, relied simply on measuring the resonant frequency of a presettable tuned circuit in the transponder. In the 1970s, transistor technology brought about a sharp reduction in the size, power requirements and cost of ID equipment. It also became possible to transfer more information, even if only by the application of "brute force" methods. In the late 1970s, SAW (surface acoustic wave) technology provided a breakthrough in transponder design. I quote from a seminar paper by Robert Gouldson and Graham Murdoch (Magellan Technology Pty Ltd, Perth): "SAW transponders utilised a tapped microwave acoustic delay line to generate a coded sequence of microwave pulses - a very elegant solution to the production of ID codes". With the level of miniaturisation available in the 1980s, it has become possible not only to reduce radically the size and cost of both interrogators and transponders but to record, store and retrieve large amounts of digitised data under what would once have been intolerable environmental conditions. Progress in ID/information technology over the past five years is described in the literature as "drama tic", with the industry reportedly set to take off in a big way on farms, in factories, bulk stores, transport, etc right through to personnel management. Protocols & pipedreams Whether this can happen in the same structured way as the bar code revolution is debatable. If the ID/information industry does "take off" , it may well do so in the manner of pen full of startled chooks: madly and in every direction at once! Last month I mentioned that Dr Hammond of the AGBU had expressed the fervent hope that a common protocol could be adopted for recorded data in the livestock industry, to simplify the exchange of information. Perhaps " forlorn" would have been a better word. In a survey of their needs, breeders, dairy farmers, pastoralists, beef producers and abbatoir operators have at least agreed that NOVEMBER 1989 87 Typical Electronic ID Systems e ACTIVE MICROWAVE: a 10.5 GHz interrogation signal triggers a battery powered transmitter on the transponder which repetitively retransmits a 2 .45GHz signal modulated by the ID code. 64 bits, including 30 bits reprogrammable "on the fly". Range: 2 metres. • ACTIVE UHF: a 930MHz interrogation signal is reflected by a field disturbance antenna on the transponder. A battery powered circuit switches the antenna in accordance with the ID code. 128 bits, re-programmable by purchaser. Range: 40 metres. • ACTIVE HF: an optical trigger pulse activates a battery powered transmitter on the transponder. Re-transmitted HF signal is modulated by the ID code . 20 bits or more. Range: 30 metres, depending on the optical path and future ID/information technology must be better than present manual methods. But their expectations of such equipment were diverse in the extreme: its physical characteristics, ruggedness, role, operating life, portability, reading distance, data capacity, compatibility with data banks, and so on. Some of the requirements were extravagant, others impractical with present technology. A none-too-optimistic Dr Hammond summed up the situation thus: "The inital approach by virtually all concerned is to envisage one ideal system that copes, cost effectively, with all requirements and suits all environments. A single ideal system is a pipe dream. "There is a range of specific and quite different operating environments and requirements. The most cost effective specifications for each will be quite different. In addition, there are at least half a dozen generic technologies, all of which are immature. "Strong competition should be encouraged if the best systems are to be developed and made available at lowest cost". 88 SILICON CHIP beam intensity. • ACTIVE LF: a 132kHz interrogation signal activates a battery powered transmitter on the transponder. The 132kHz signal is divided down, modulated by the ID code and re-transmitted. 64 bits, reprogrammable by purchaser. Range: 3 metres. • PASSIVE MICROWAVE: interrogation signal swept between 2.9GHz and 4.1 GHz at 4kHz rate. Preset cavities in transponder antenna resonate at selected frequencies. Timing of signal reflected by the cavities with respect to sweep frequency give the ID coding. 65 bits preset at manufacture. Range: 2.5 metres. • PASSIVE UHF: a pulsed 91 5MHz interrogation signal converted into surface acoustic waves on a lithium niobate crystal in the Typical systems Competition there certainly will be. Typical system concepts are listed by Murdoch and Gouldson (mentioned earlier) and are summarised in the accompanying panel. Incidentally, the description " Active" means that the transponder has its own battery such as a longlife lithium cell, the same as used in heart pacemakers. They are very reliable, with a shelf life of 15 to 20 years, but the actual in-service life depends on usage. "Passive" transponders have no battery. Some simply reflect the interrogation signal back to its source, but modified in some way in accordance with in-built ID coding. Others convert portion of the interrogation signal into electrical power to operate their own internal circuitry. Some passive transponders use both techniques. Compared with passive transponders, active systems offer greater reading range and higher data capacity, and can support more complex functions such as a reprogrammable memory and a real time clock. They can usually get by with a weaker interrogation transponder. Delayed versions of the interrogation pulse are retransmitted as per the ID code. 30 bits preset at manufacture. Range: 2 metres . • PASSIVE HF/LF: a low frequency field powers the transponder. An RF interrogation signal is reflected by a field disturbance antenna on the transponder which is switched in accordance with the ID code. 34 bits, programmable by the purchaser. Range: 0.6 metres. • PASSIVE LF: a 1 00kHz interrogation field is received by the transponder. A 50kHz subharmonic field is generated by selectively connecting the tuned antenna. The sub-harmonic field is phase modulated by the ID code and re-transmitted. 30 bits or more normally preset on manufacture. Range: 1 metre. signal and may therefore be easier to license. Without batteries, on the other hand, passive transponders tend to be less expensive and more reliable over long periods, even to offering "unlimited" service life. Either way, systems using high signal frequencies are more compact and efficient, and have better range, directivity and speed of data transfer. On the other hand, lower frequency systems are less sensitive to antenna orientation, less susceptible to man-made electrical interference and on-site contaminents and again, easier to license. One other point: the smaller the transponder, the smaller the effective antenna, and the less the potential reading range. There is much more in the discussion papers but enough has been said to indicate that ID design engineers are faced with a daunting array of variables to sort out. If they also manage to come up with industry standards, they'll have really earned their keep. "Smart" tags Finally , among the articles February 1988: 200 Watt Stereo Power Amplifier; Deluxe Car Burglar Alarm; End of File Indicator for Modems. March 1988: Remote Switch for Car Alarms; Telephone Line Grabber; Endless Loop Tape Player. April 1988: Walkaround Throttle for Model Railroads; pH Meter for Swimming Pools; Slave Flash Trigger; Headphone Amplifier for CD Players . May 1988: Optical Tachometer for Aeromodellers; High Energy Ignition for Cars; Ultrasonic Car Burglar Alarm. June 1988: Stereo Control Preamplifier; Breakerless Ignition For Cars; Mega-Fast Nicad Battery Charger. July 1988: Fitting a Fuel Cut-Off Solenoid; Booster for TV & FM Signals; The Discolight Light Show. August 1988: Remote Chime/Doorbell; High Performance AC Millivoltmeter; Getting the Most Out of Nicad Batteries. September 1988: Hands-Free Speakerphone; Switchmode Charger for 12V Gel Batteries; Vader Voice. October 1988: Stereo FM Transmitter; High Performance FM Antenna; Matchbox Crystal Set; Electronic House Number. November 1988: 120W PA Amplifier Module; Poor Man's Plasma Display; Car Safety Light; How to Quieten the Fan in Your Computer. December 1988: 120W PA Amplifier; Diesel Sound Generator; Car Antenna/Demister Adaptor; SSB Adaptor for Shortwave Re·ceivers . January 1989: Line Filter for Computers; Proximity Detector for Cars; How to Service Car Cassette Players. February 1989: Transistor Beta Tester; Minstrel 2-30 Loudspeaker System; LED Flasher for Model Railways; Lightning & Electronic Appliances. March 1989: LED Message Board; 32-Band Graphic Equaliser; CD Compressor; Amateur Band FM Receiver April 1989: Auxiliary Brake Light Flasher; What You Need to Know About Capacitors; Telephone Bell Monitor/ Transmitter. May 1989: Electronic Pools/Lotto Selector; Synthesised Tom-Tom; Biofeedback Monitor For PCs; Simple Stub Filter For Suppressing TV Interference. June 1989: Touch-Lamp Dimmer; Passive Loop Antenna For AM Radios; Universal Temperature Controller; Understanding CRO Probes. July 1989: Exhaust Gas Monitor; Extension for Touch-Lamp Dimmer; Mains Hum Sniffers; Ultrasonic Car Alarm. August 1989: Build A Baby Tower AT Computer; Studio Series 20-Band Stereo Equaliser; Garbage Reminder; Introduction to Stepper Motors. September 1989: 2-Chip Portable AM Stereo Radio; Alarm-Triggered Telephone Dialler; High Or Low Fluid Level Detector; Simple DTMF Encoder. October 1989: Introducing Remote Control; FM Radio Intercom For Motorbikes; 1 Mb Printer Buffer; Installing A Hard Disc in the PC Note: November 1987, December 1987 & January 1 988 are now sold out. Use this handy form to order your back copies ~ r---------------------------------- • --, Please send me a back issue for: D February 1 988 D March 1988 D April 1 988 D May 1988 D June 1988 D July 1988 D August 1988 D September 1 988 D October 1 988 D November 1 988 D December 1 988 D January 1989 D February 1989 D March 1989 D April 1989 D May 1989 □ June 1989 D July 1989 D August 1989 D September 1 989 D October 1989 Enclosed is my cheque/money order for $ _ _ _ _ _ _ or please debit my □ Bankcard □ Visa Card □ MasterCard Signature _ _ _ _ _ _ _ _ _ _ Card expiry date_ _ / _ _ / _ _ Name_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ __ _ __ (PLEASE PRINT) Stree~-----------------------Suburb/town. _ _ _ _ _ _ _ _ _ _ _ _ Postcode.____ Price: $A5 .00 each (includes postage). Overseas orders add $A 1 .00 per issue for postage. NZ & PNG orders are sent by air mail. Detach and mail to: SILICON CHIP PUBLICATIONS PO BOX 139 COLLAROY BEACH NSW 2097 OR FAX: (02) 982 9553 ~-------------------------------------~ NOVEMBER 1989 89 THE WAY I SEE IT - CTD drawn to my attention by Dr Royden Lake was one in the "IEE Review" (UK) for June 1989: "Smart Tags, The Distributed Memory Revolution", by Peter Hewkin of Scientific Generics. Peter Hewkin defines smart tags as "small devices containing a combination of memory, data processing and communications capabilities. They can communicate without physical contact with purpose-built stations over a range from a few millimetres up to several metres". He goes on to explain that smart tags typically contain semiconductor memories (ROM, EPROM or EEPROM), along with stamped, etched or wound inductors and miniature batteries in the case of active devices. Smart tags range in size, says Peter Hewkin, from that of a brick down to a capsule a few millimetres in diameter. In price, they range from around 30 pounds sterling ($A60) to less than one pound for simple devices holding only a few bits of memory. Certainly, all the transponders (tags?) covered in the accompanying panel respond to an electronic signal and all have a memory function of some kind. Some are userprogramma ble, others are not. Presumably they're all "smart", with some more so than others! According to Peter Hewkin, car manufacturers are also moving away from reliance on a central factory database to the use of smart tags which attach to each individual body shell and ensure that the options nominated by the customer and dealer are available in time and observed at each station in the assembly line. The tag could also be used to record faults which need to be corrected before despatch. In other situations, smart tags can selectively control the movement of individual animals, warn if miners approach too close to dangerous machinery and, in security situations, selectively grant or deny access to particular individuals, depending on how their tag is programmed. More intelligent, interactive tags (cards?) are also in the pipeline for financial transactions, even to the point where transactions would be possible without even removing them from one's wallet. That thought stopped me in my tracks. What a challenge for a new breed of "hacker". Get yourself an interrogator, ride a crowded suburban train and see how many pockets or purses you can pick electronically - without touching the wallet inside! Isn't technology wonderful? ~ Simple program for resistor calculations Do you need to make up non-standard resistor values? This simple program will show you what series or parallel combinations from the E12 range can be used. You simply type in the value you want plus the tolerance. By STEVE PAYOR Ever tried to measure 240V AC on the ohms range of your multimeter and burnt out a string of odd-value resistors? Ever calculated the resistor values for an active filter and found that none of them were anywhere near a standard E12 value? If so, the following BASIC program will help. It will tell you whether the resistor value(s) you 90 SILICON CHIP are seeking can be made up from two E12 values in series or parallel, within a specified tolerance. The sample printout shows 9 possible ways of making up a 1230 ± 1 % resistor. In choosing the most suitable combination, a little thought should be given to the wattage and tolerance of the individual resistors. For example, if this resistor is to be used in an am- meter, you would choose a combination where the two E12 resistors were fairly close in value to maximise the power rating; eg, 3900 1 % in parallel with 1800 1 %. Alternatively, if dissipation is not a problem, as in an active filter, then 1200 1 % in series with 3.30 10% would be another possibility. The program performs a "brute force" search of all possible series and parallel resistor combinations, to see which fall within the required tolerance. This is not a very efficient approach but even on the slowest IBM compatibles, the search only takes 10 seconds. Lines 20 to 100 set up (also by brute force) an array of 7 decades of E12 values, from .01 to 100,000. The desired resistance should be between 1 and 999.9; ie, within the middle 3 decades of this table. This