ARINC 708
From Wikipedia, the free encyclopedia
ARINC 708 is a specification for airborne pulse Doppler Weather radar systems primarily found on commercial aircraft. ARINC708 and the Honeywell Picture bus are the predominant avionics data bus for most aircraft today.
Contents |
[edit] Technical Description
ARINC 708 uses a transformer-coupled Manchester encoded signal, like the MIL-STD-1553 protocol. Termination of the bus is essential for good signal quality. Furthermore, the bitstream is continuous, requiring good re-synchronization to the bit stream. Data frames are 1600 bits long with the header portion of the frame consisting of parameters such as range, tilt, gain, status, etc. The data portion is organized into 256 range-bins per scan angle value. Each range bin contains a color value to indicate the intensity at that position. Settings for the ARINC 708 system is typically controlled using an ARINC 429 interface.
[edit] Avionics Weather Radar Systems
Commercial Weather Radar Systems consist of the following items:
Antenna T-R Unit (Transmit-Receive Unit) CDU (Control-Display Unit) Display
[edit] Variations
Variations from the standard specification include variable word length and non-standard amplitude values. Some implementations also require non-standard re-synchronization.
[edit] See also
- ARINC 429 protocol used to control radar.
- MIL-STD-1553 protocol is electrically similar to ARINC 708.
- We have used Ballard Technology equipment to test our CDU, and T-R unit with ARINC 429 build in.
