Patent ID: 6381501
Filing Date: 2002-04-30
Classification: G05B

Abstract:
A data logging apparatus for use as control equipment in a facility or machine, comprising:a plurality of programmable logic controllers connected to each other through communications links, one of said programmable logic controllers being an administrative programmable logic controller which includes a memory; a factory automation (FA) controller connected to said administrative programmable logic controller through a communications link, said administrative programmable logic controller executing a data logging program which accumulates in said memory data generated by the administrative programmable logic controller and data generated by others of said programmable logic controllers, and which sends data accumulated in said memory to said FA controller, such that said administrative programmable logic controller acts as a buffer between said plurality of programmable logic controllers and said FA controller; and a program data preparing means provided in said FA controller, for preparing data for said data logging program running on said administrative programmable logic controller and for a data logging program running on said FA controller, wherein data accumulated by the administrative programmable logic controller according to said programs is successively processed by said FA controller according to data prepared by said program data preparing means.