Improving error containment and reliability of communication subsystems based on Controller Area Network (CAN) by means of adequate star topologies

Abstract

[eng] Controller Area Network (CAN) is a field bus communication protocol widely used in distributed control systems. Nevertheless, CAN presents some dependability-related shortcomings that may discourage its use in highly-dependable applications. One of its major limitations is that it relies on a non-redundant bus topology with scarce error-containment and fault-tolerance mechanisms. To demonstrate that it is possible to overcome this limitation and improve reliability of CAN-based systems by means of adequate star topologies, we developed two CAN-compliant stars called CANcentrate and ReCANcentrate. CANcentrate is a simplex star aimed at improving error containment. Its active hub includes novel mechanisms to contain errors at their ports of origin. ReCANcentrate is a replicated star that includes two hubs, similar to the one of CANcentrate, to further provide fault tolerance. We quantitatively corroborated the reliability benefits of these stars by modelling equivalent systems relying on them and on CAN by means of Stochastic Activity Networks.