19 September 1998

Chips are down on millennium bug

The millennium bug could hit you where it really hurts, and that doesnt mean your pocket, warns Tia Rund.

Fifteen months and counting… The year 2000 is fast approaching. Youve think youve heeded all the warnings about the millennium bug, but has it occurred to you that its not just computers that stand to suffer? The Health and Safety Executive says its not overstating the case by saying that the bug could put human safety at risk.

Rick Brunt, the HSE agricultural inspector who heads its year 2000 project, gives the example of a twine-tying system on a baler.

"First of all, by the time you come to use the baler in, say, June, the chance is youll have forgotten all about the millennium bug," he starts. But if the chips controlling the tying operation have a date function, the machine may not know how to react to the muddled signals."

The real difficulty, he continues, is the unpredictability of potential failure. The HSEs prime concern in this example is that while youre investigating why the baler has stopped, it could suddenly begin to interpret the electronic signals and start up again of its own accord. Cue another accident statistic.

So, how does the HSE recommend you safeguard yourself and your staff? Unfortunately, theres no quick guide, says Mr Brunt. Whats important is that year 2000 is treated as a serious issue requiring pre-emptive action to remedy potential problems.

"First of all," he says, "its vital to realise this isnt restricted to computers in the desktop PC sense. There are many pieces of machinery and equipment with programmable electronic systems – or PES. You may not even realise theyre there. And, even if theres no obvious date-related function, that doesnt necessarily mean the feature isnt there."

Thats because chips used in control panels, for instance, are usually bought off the shelf, so tend to have additional functions not used by a manufacturer. "The machine itself may not be date sensitive but, unbeknown to the user, the software might rely on the date."

Assess each PES to establish how much you depend on it for safety, and also whether its date dependent. For this youll need the co-operation of your supplier.

Are you compliant?

In each case, ring the manufacturer and ask whether the electronic systems on your machine and model are millennium bug compliant. Patience and persistence are likely to be the order of the day, as there will need to be a certain amount of backtracking through the supply chain, warns Mr Brunt.

Also its sensible to request some written assurance. After all, it may be more than your commercial health thats at stake.

If that assurance cant be given straight away, you will need to work closely with the manufacturer to see whether reprogramming or replacement of the particular component is necessary. "Our contact with the Agricultural Engineers Association and its members suggests that theyre very aware they have this work to do. Im sure they realise it would be bad business for them to let their customers down."

Why the bug will bite before 2000

Many computers and other software applications recognise the year by its last two digits only. When the date changes to 2000, some will recognise 00 as 1900; others may default to another year. In either case, systems which use these incorrect year numbers in arithmetic calculations may produce incorrect results or fail entirely.

Plus, the year 2000 also happens to be a leap year. Some systems are incorrectly programmed for this, claims the HSE.

However, theres also a more general problem associated with whats called date discontinuity where system time goes out of sync with actual time. For instance, some systems are equipped with clocks which calculate time from a fixed point. When the register which clocks up time is full, it will overflow like a car odometer and show zero, which the software interprets as the original date of origin.

This is the situation with certain global positioning satellites. On 22 August next year, most inconveniently for combine harvester applications, several satellites will revert to a January 1980 dateline unless tricky re-programming is successful.

Dates to stay indoors

Jan 199999 used by programmers as a shutdown command

22 Aug 1999The GPS week number register rolls over to read zero

1 Sept 1999999 used by programmers as a shutdown command

9 Sept 19999999 used by programmers as an end of file marker

1 Jan 2000The well-publicised year 2000 issue

29 Feb 2000Some systems misprogrammed. 2000 is a leap year.

1 Mar 2000Wrong day of week if not programmed for leap year.

31 Dec 2000The 366th day of the leap year

1 Jan 2001Wrong day of week if not programmed for leap year.

What can go wrong?

&#8226 Yield mapping on the combine

&#8226 Programmable functions or drills and sprayers such as tramlining

&#8226 Irrigation systems

&#8226 Engine management systems on tractors

&#8226 Balers