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Browse Prior Art Database

Piggy-Back Controller

IP.com Disclosure Number: IPCOM000117575D
Original Publication Date: 1996-Apr-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Meyer, D: AUTHOR

Abstract

Very often the upgrade capabilities of older (production) machines are restricted due to the limitations in the machine controller. Either the size of the controller or the number of input/output lines are insufficient and cannot be extended or the programm/source code is unknown since it is usually the property of the manufacturer. In many cases, the controller may even be hardwired and not free by programmable. Also, major changes to the machine controller always bear the risk of introducing serious flaws to parts of the machine functions which were properly operating so far.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Piggy-Back Controller

      Very often the upgrade capabilities of older (production)
machines are restricted due to the limitations in the machine
controller.  Either the size of the controller or the number of
input/output lines are insufficient and cannot be extended or the
programm/source code is unknown since it is usually the property of
the manufacturer.  In many cases, the controller may even be
hardwired and not free by programmable.  Also, major changes to the
machine controller always bear the risk of introducing serious flaws
to parts of the machine functions which were properly operating so
far.

      We have overcome the limitations of the controller of such an
older machine and we have modified and added functions to the machine
by piggy-backing an additional controller.  The hardware and software
of the old controller were not modified at all.  The original
functions were never at risk and the use of the machine was not
impaired by lengthy debugs.  The piggy-back controller has two
functions:
  1.  It "deceives" the old controller by simulating the existence of
       un-modified system and process so that the old controller does
       not "recognize" any change in configuration or function, and
  2.  It controls all modified and added hardware and processes.

The two functions of the piggy back controller are completely
independent except for a synchronization.

      In our specific application we have replaced a single s...