ARINC 717 is a technical specification for an avionics data bus used for flight data acquisition and recording systems.

Data is streamed continuously over the bus and is organized in frames and subframes. Each frame contains 4 subframes, 1 second long each. Each subframes contains 64, 128, 256 or more words of 12-bit each. The first word of each subframe has to be a synchronization word. The synchronization word is specific to each subframe.