TTP/A: A Low-Cost, Highly Efficient, Time-Triggered Fieldbus Architecture

TTP/A is the fieldbus protocol of the Time Triggered Architecture (TTA). It provides periodic transmission of realtime data and allows for on-line configuration, diagnostics, and maintenance by use of an interface file system. It is well integrated with the TTP/C protocol and is designed to meet the requirements of a low-cost sensor/actuator bus. TTP/A is a master-slave protocol where the master establishes a common time base within a TTP/A cluster. Since the master establishes the time base prior to the communication of slaves, the protocol can be implemented with low-cost on-chip RC oscillators for the slaves. Using a standard UART-based serial interface as physical layer, the slave TTP/A protocol can be implemented in very low cost Commercial Off-The-Shelf (COTS) hardware.