Programmable controller processor with an intelligent functional module interface

Abstract From the Canadian patent

A programmable controller has a rack that houses and electrically connects a number of I/O modules and a processor module. The processor module includes a external communication network interface, a system memory, a processor section which executes a user-defined control program and a I/O interface that handles the exchange of data with the other modules. The I/O interface has circuitry for pre-processing data from defined input modules, thereby relieving the processing section of certain tasks, The shared memory contains information defining the input module from which to obtain data for pre-processing and the bits of that data to be examined for specified logic level transitions. The …