HOME | back

The count-down is on!

New Year’s Eve 1999/2000 will in many respects be a special event. And as sure as there will be a popping of innumerable champagne corks, so also must real-time clocks smoothly keep in line with the year 2000, particularly when date indications are used for calculators. In this connection, the definition rules DISC PD2000-1 of the British Standards Institution are generally accepted. They require that device should continue to work fault-free at the change-over to the new millennium. This also involves the correct recognition of 29th February 2000 as a leap-day, even when representation of the number of the year is only two-digit, as it is in most automation devices.

Naturally, all the automation systems of ABB Switchgear and Controlgear Engineering comply with these BSI rules with their clock functions. This includes the systems Advant Controller 31 and ABB Procontic CS31 with the central processing units 07 KR 91, 07 KT 92, 07 KT 93 and 07 KT 94, as well as ABB Procontis T300 with central control unit 35 ZE 94. These systems use a two-digit year representation.

Even if its date changes correctly from 99 to 00, there is still the possibility that its year indication will be incorrectly processed in the application. For example, calculating the period between the year 98 and the year 00 will produce the result -98. It is consequently the responsibility of the designer and user to use the date correctly and to ensure operation into the next millennium.

The measure to adopt is in this case without doubt to convert the two-digit representation into a four-digit representation before it is used in calculation. How this happens represents a simple example of ABB Switchgear and Controlgear Engineering to be incorporated in the user program.

The date indication in the ABB Procontis T200 automation system is four-digit from the outset, so that all problems can be avoided without special measures. Automation systems, particularly older ones, which have no clock functions are of course not affected by the turn of the millennium.

ABB indicating and operating devices, e.g. the MT 60, only use the data for the display or pass it on to the connected control processing unit. The other functions are not affected and continue to work independently of the date. Older versions can give the wrong date with effect from 29th February 2000, but it can be correctly reset again with effect from 1st March 2000. ABB Switchgear and Control-gear Engineering offer an upgrade for applications in which this is a problem.

Finally, the WIZCON visualisation and master-computer software also take account of the new standard. An upgrade is available for the older Windows versions. In the new versions, the historic turn of the year is of course already taken into consideration.