Tovar, EduardoVasques, FranciscoBurns, Alan2014-01-302014-01-3019990967-0661http://hdl.handle.net/10400.22/3531Fieldbus communication networks aim to interconnect sensors, actuators and controllers within process control applications. Therefore, they constitute the foundation upon which real-time distributed computer-controlled systems can be implemented. P-NET is a fieldbus communication standard, which uses a virtual token-passing medium-access-control mechanism. In this paper pre-run-time schedulability conditions for supporting real-time traffic with P-NET networks are established. Essentially, formulae to evaluate the upper bound of the end-to-end communication delay in P-NET messages are provided. Using this upper bound, a feasibility test is then provided to check the timing requirements for accessing remote process variables. This paper also shows how P-NET network segmentation can significantly reduce the end-to-end communication delays for messages with stringent timing requirements.engDistributed computer-controlled systemsP-NET fieldbus networksReal-time communicationsMessage response time analysisjournal article10.1016/S0967-0661(99)00073-8