Time Triggered Protocol

Time Triggered Protocol

Time Triggered Protocol [TTP] is a fault-tolerant, deterministic Field Bus for safety-critical aerospace applications first implemented in 2004.
The RS-485 interface has been the de facto physical layer standard for TTP [RS-485 Interface Description]. The two channels operate either asynchronous or synchronous over a bus or star Interface Topology.
Asynchronous channels operate using self-clocking transmission encoding which can be either MFM or Manchester at a maximum data rate of 5 Mbit/s on a shared media (physical bus).
Synchronous channels transfer data at a rate between 5 and 25 Mbit/s [maximum bit rate] or 50Mbps throughput using both channels.

Time Triggered Protocol is used for power generation and environmental control systems of commercial aircraft such as the Boeing 787 and Airbus A380.
Military aircraft using the MIL-1553 Avionics Interface utilize TTP as SAE AS6003 [TTP 1553]. Additional Avionics Interface Descriptions.

TTP Signaling
Signal name Signal Function
RxD [1:0] Receive channel, dual channel
RxCLK [1:0] Receive clock
RxDV [1:0] Receive data valid
RXER [1:0] Receive error
TxD [1:0] Transmit data, dual channel
TxCLK [1:0] Transmit clock
CTS [1:0] Transmit enable

Time Triggered Protocol Standards

SAE AS6003 TTP Communication Protocol
SAE AS6003/1; TTP Communication Protocol over MIL-1553 [not yet released]
SAE AS6003/2; TTP Communication Protocol over RS-485 [not yet released]
SAE AS6802; Time-Triggered Ethernet (TTEthernet) Standard [not yet released]

TTP Interface ICs

austriamicrosystems TTP-C2NF Communication Controller [AS8202NF]

The interface is designed to run at 25 Mbit/s and to be gluelessly compatible with the commercial 100 Mbit/s Ethernet MII (Media Independent Interface) according to IEEE standard 802.3 (Ethernet CSMA/CD). Connecting the synchronous TTP bus unit to a 100 Mbit/s Ethernet PHY is done by connecting TxD, CTS, TxCLK, RXER, RXCLK, RxDV and RxD of any channel to TxD0TxD0, TxEN, TxCLK, RXER, RXCLK, RxDV and RxD0 of the PHY's MII. The pins TxD1, TxD2 and TxD3 of the PHY's MII should be linked to VSS. The signals RxD1, RxD2, RxD3, COL and CRS as well as the MMII (Management Interface) should be left open or can be used for diagnostic purposes by the application

TTP Applications include automotive (by-wire braking, steering, vehicle dynamics control, drive train control), aerospace (aircraft electronic systems), industrial systems, and railway systems.
RTCA; Radio Technical Commission for Aeronautics

PC motherboard

Distributor rolodex Electronic Components Electronic Equipment EDA CDROM Software Engineering Standards, BOB card Cabled Computer Bus Electronic Engineering Design Table Conversion DB9-to-DB25.
DistributorsComponents Equipment Software Standards Buses Design Reference

Modified: 1/9/12
Copyright © 1998 - 2016 All rights reserved Larry Davis