this invention relates to a programmable logic controller inputs - outputs system comprising a processing unit provided with a memory and at least one inputs - outputs coupler provided with a coupler memory and forming the link between sensors and pre - actuators and the processing unit characterized in that exchanges between the processing unit memory and each coupler memory are structured by logical channels carrying out a job function and grouping all or some physical channels of a coupler and in that the memory of the processing unit contains objects related to each logical channel that form a data structure with standardized contents , these objects being exchanged with the coupler memory through a user program by means of an instruction set .