Y2K Failure In CNC Process

From: Steven Pollack (themissinglink@eznetinc.com)
Date: Mon Aug 02 1999 - 09:30:52 EEST


Equipment Type PLC
                Industry Sector Manufacturing
                PC or Computer based No
                System Age Unknown
                CNC Milling Machine.
                The system is used to manufacture aircraft parts and is
controlled by PLCs.
                Description of the Problem
                - At the 31/12/1999-1/1/2000 transition, the PLC's BIOS
resets from 31/12/99 to 4/1/1980;
                - NC program data with the current date (1/1/2000) is then
downloaded from the DNC
                - There will now be a date conflict between the downloaded
NC data and the internal date.
                How was it Identified
                Information from supplier states that current 'x' series
PLC and operating system software
                are BOTH non-compliant.
                Analysis and rollover testing confirmed the non-compliance
of these PLC and this version of
                the operating software.
                What was the Solution
                Upgrade of operating system in 3 stages.
                Consequences for the SYSTEM Erroneous Result
                Consequences of failure to the BUSINESS
                Confusion over NC files which are downloaded over the site
network due to date
                There are three of these machines dedicated to the same
task, all are identical and
                therefore consequence of failure is increased threefold. As
far as known, these are the only
                machines available to manufacture the above aircraft parts
to the proven method at this site.

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