ABSTRACT
The Time-Triggered Protocol (TTP) is a communication protocol for distributed fault-tolerant real-time systems. This chapter describes the communication services support the predictable message transport with a small variability of the latency. In the aerospace domain, the Honeywell Modular Aerospace Control (MAC) has been developed using TTP as a backplane databus for intermodule communication. The TTP protocol supports external clock synchronization using a time reference such as GPS. The fault-tolerant clock synchronization maintains a specified precision and accuracy of the global time base, which is initially established by the restart and start-up services when transiting from asynchronous to synchronous operation. The diagnostic services in conjunction with the a priori knowledge about the permitted behavior of nodes are the basis for the fault isolation services of TTP. The configuration services offer flexibility by switching between predefined modes or programming new communication schedules into the system.
