A new method to build the FF schedule time list

In a single segment Foundation Fieldbus system, a link active scheduler, according to a pre-defined schedule time list, controls all remote periodic message transfers between different field devices on bus. The remote periodic message not only has time constraints but also often has precedence constrains. In this paper a new method to build the schedule time list is proposed, in which both time constraints and precedence constrains are considered and described by modifying release time and deadline. The method proposed is based on slack time monotonic and local search. An example of application shows the process of building FF schedule time list.