Many airborne installations, in particular for large airframes, require data acquisition units (DAUs) to be located all around the aircraft in order to be close to the sensors and avionics buses being monitored. The traditional implementation of a large system has involved several different types of DAUs for different functions, using different standards of interconnects which leads to huge wiring complexity.
Moving to a standardized network solution allows the introduction of commercial off-the-shelf (COTS) hardware with standard network management and protocols. This reduces the overall wiring complexity and benefits from a well-proven capability in industrial and commercial applications. Ethernet is the ideal choice of network to support the programming, data transfer and synchronization requirements – in particular in light of recent evolutions in time synchronization and the establishment of networking standards for airborne applications.
With the Ethernet backplane controller, the Acra KAM-500 becomes an Ethernet network node and fully IEEE 1588 compliant; meaning all data across all DAUs is synchronized to the order of nanoseconds using the Precision Time Protocol (PTP). All setup, data acquisition and synchronization is done over a single Ethernet connection, leading to significant savings in wiring complexity and weight.
Standard Ethernet switches can be used in a data acquisition network, eliminating the need for expensive custom-built ‘master control units’ or ‘intelligent multiplexers’. Curtiss-Wright develops and manufactures ruggedized Ethernet switches and IP recorders for the harsh conditions found in the aerospace environment.