Simulation and Verification of an Improved Membership Fault-Tolerant Service in TTP/C

Time-Triggered Protocol (TTP) bus is a kind of multiple accessing bus with fault-tolerance mechanism for real-time communications, e.g. for distributed control systems. Fault-tolerance for the Group Membership service of TTP/C can be comprehensively verified by running a suite of simulation models, which designed and operated with the TTP's distributed clock synchronization mechanism, and implemented under MAT-LAB/Simulink/SimEvents environment. The original membership fault-tolerant service (MFS) algorithm can provide fault-tolerant service guarantees for nodes that access the bus in exclusive time slots regardless sharing slots. On the other side, an improved membership fault-tolerant service (IMFS) algorithm is presented to guarantee nodes with bus access in multiplexed time slots and is designed to be compatible with nodes with bus access in exclusive time slots. During bus accessing, the IMFS algorithm can rejoin any node that has a transient failure in the membership within a bounded time interval; the IMFS algorithm can also block any node that occurs a permanent failure while keeping the other nodes' normal bus accessing. Case studies and simulation results show that our IMFS algorithm is compatible with the MFS algorithm, either with multiplexed time slots or without it, and has lower amount of packet losses.