BOHEMIA, N.Y., 18 Oct. 2010. Data Device Corp. (DDC) in Bohemia, N.Y., has combined the Time Triggered Protocol (TTP) with the MIL-STD-1553avionics databus physical layer to achieve a flight-critical TTP avionics databus implementation for military and commercial aviation applications.
"DDC has demonstrated a communication system using commercially available TTP controllers combined with MIL-STD-1553 physical layer transceivers running at 4 megabits per second on a 430-foot bus with 10 stub connections," says Mike Hegarty, DDC's principal marketing engineer. "The results of the testing showed that MIL-STD-1553 can be used to provide TTP with a physical layer that is appropriate for even the most demanding aerospace applications such as flight control."
RS-485 has been the de-facto physical layer standard for TTP, and has been used in commercial applications since 2002, including power generation and environmental control systems of aircraft such as the Boeing 787 and Airbus A380, DDC officials say.
While TTP offers a deterministic protocol for implementing real-time distributed control systems, the low transmit levels and loosely defined receiver characteristics of RS-485 limit the ability to use it in flight-critical aerospace applications.
By combining commercial TTP controllers with a MIL-STD-1553 physical layer, DDC has developed a cost-effective method for commercial aircraft to reap the benefits of military proven dependability, company officials say.
MIL-STD-1553 is designed for aircraft applications, and has been the military databus standard for decades. MIL-STD-1553 benefits include well defined transmitter and receiver characteristics, isolation, lightning protection, and fault tolerance, along with certification and validation advantages.
TTP running over a MIL-STD-1553 physical layer is yet another demonstration of DDC's continued commitment to advancing the field of military, aerospace, and commercial data bus interfaces, extending data bus speed while preserving safety and reliability.
For more information contact DDC online at www.ddc-web.com. For those willing to give DDC their e-mail addresses, the company offers a white paper outlining the evolution of MIL-STD-1553 online at www.ddc-web.com/Pub/85/567.ashx.