Re: Y2K Failure In CNC Process

From: Chris Sutcliffe (
Date: Mon Aug 02 1999 - 11:19:54 EEST

Dear All

Surely this does not apply to all CNC machines. May I suggest that if
contributors are going to post this type of information on the list that
they qualify it with the make and model of the machine.

Dr. Chris. Sutcliffe
Rapid Prototyping and Micromanufacture Research
Product Innovation and Development Centre
Department of Engineering
3 Brownlow St.
Liverpool L69 3GL

(0151) 794 8022 Direct
(0151) 794 8021 Secretary
01893 209 556 Bleeper
-----Original Message-----
From: Steven Pollack <>
To: <>
Date: 02 August 1999 08:22
Subject: Y2K Failure In CNC Process

>Equipment Type PLC
> Industry Sector Manufacturing
> PC or Computer based No
> System Age Unknown
> Application
> 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
> network;
> - 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
> discrepancies.
> 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.
>For more information about the rp-ml, see

For more information about the rp-ml, see

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