Fibre Channel Time Synchronization for Automated Testing

Abstract

Fibre Channel networks are used in a variety of modern avionics applications, mainly due to their high speed, low latency, and deterministic nature. Time synchronization of independent end-systems on a network is an important feature necessary for avionic systems that are real-time, safety critical, and fault tolerant. Fibre Channel can be configured as a deterministic network, by using an in-band synchronization protocol to synchronize the clocks of attached nodes thus allowing autonomous synchronized data transmissions. A synchronized message sent out periodically can be used to trigger the relative time start of each network time frame or window. Using this approach, the beginning time (TO) is determined each time the synchronization message is transmitted, as opposed to setting up a global clock between each of the nodes. This “time-triggered” synchronization must be accurately characterized to understand the deterministic timing of the network. This paper covers how the Fibre Channel “time-triggered” in-band synchronization operates and the testing used to characterize the deterministic Fibre Channel network timing.