The ASIU-E and the newer GPCU, can be supplied with custom firmware to operate between a 1553 interface (BC/RT/BM) and multiple Discrete inputs and Outputs (28v/Open and Ground/Open types).
The standard 1553 interface is dual-redundant per MIL-STD-1553. 1553 BC, RT, and Monitor modes can be used. Customized solutions allow for additional discrete inputs and outputs.