TTP Frame Structure Analysis & Diagnostic Software

Introduction : The TTP (Time Triggered Protocol) is a communication system for deterministic and time triggered networks in automotive and safety critical applications.

Key components of TTP Frame

• Rounds and Slots: Communication is structured into periodic rounds, each containing a sequence of time slots.
• TDMA and Collision Free Communication: Each node is assigned a specific time slot to transmit its frame, ensuring collision free data transfer.
• Firewors Frame: Every round begins with a special control frame, the “fireworks” frame, sent by the master node to synchronize all other nodes in the cluster.
• Data Frames: After the fireworks frame, each node transmits its data frame during its assigned time slot.
• Variable Frame Size: The size of the data frame can be adjusted by the node, ranging from 2 to 240 bytes, depending on the communication requirements.
• Frame Protection: Each data frame includes a 24-bit Cyclic Redundancy Check (CRC) to ensure data integrity.
• Round Descriptor List (RODL): The specifications for each round, including the frame size and slot position for each communication action, are defined in a pre-configured Round Descriptor List (RODL).

TTP Frame Structure

The Time-Triggered Protocol (TTP) frame format is based on a Time-Division Multiple Access (TDMA) scheme where frames are sent at predetermined times within a time slot.

Each TTP frame follows a defined schedule and fixed structure including header, payload and CRC.

TTP Protocol Data logger tool

Summary: Diagnostic software for TTP frame structure enables visibility into precisely scheduled, deterministic message flows which is critical for verifying timing correctness, fault tolerance and real time behavior in advanced vehicle systems.