Transmission scheduling for fieldbus: a strategy to schedule data and messages on the bus with end-to-end constraints

The transmission scheduling for fieldbus has been addressed until now to minimize the number of data. It does not take into account the temporal dependency of data. Usually, the approaches of transmission scheduling for fieldbus let to the application processes to decide whether to use old values or not. The objective of this paper is to show how to adapt Gerber's methodology to generate a scheduling table of a set of periodic and aperiodic data from application processes to be transmitted through a fieldbus, guaranteeing their end-to-end constraints; and how this can be done in according to IEC 1158. This strategy obviates the transmission of old and useless data to application, thus optimizing the fieldbus scheduling.