A175 Aitech Defense Systems SFF I/O Expansion Subsystem

The Aitech Defense Systems A175 SFF I/O Expansion Subsystem is a small add-on unit for avionics systems. With its high variety of I/O interfaces, small form factor, low power dissipation, and standard MIL-STD-1553B avionics bus interface (RT), the A175 handily meets these requirements. It can be used to expand the I/O capabilities of any avionics computer with a standard MIL-STD-1553B interface. For sensitive signals, the unit can be mounted in close proximity to sensors enabling short wiring to ensure maximum signal integrity and minimum signal loss. The A175 is ideal for expanding the capabilities of existing avionics systems, with inherent scaling capability provided by additional units that can be added as slaves to the main avionics computer. The number that can be added is limited only by the capabilities of the main avionics computer. All I/O interfaces are implemented in the unit's FPGA, with only the physical layers being dedicated devices. This minimizes power consumption, and enables convenient customization of the unit to meet specific applications. To ensure highest reliability, the A175 includes extensive Built-in Test (BIT) capabilities. Each discrete output line is routed to a dedicated discrete input to enable loopback testing. (These dedicated discrete inputs are in addition to the discrete inputs available at the I/O connectors). The FPGA compares the input and output signals and writes a health status bit for each channel to registers in the FPGA that are accessible to the avionics computer CPU via the MIL-STD-1553B link.