The master slave function is part of the standard device and doesn't need additional hardware ex-cept patch cables and splitters. The communication between the master and the slave drives uses the OP System Bus (see AP0040026EN). A beam splitter (or beamsplitter, power splitter) is an optical device which can split an incident light beam (e. a laser beam) into two (or sometimes more) beams, which may or may not have the same optical power (radiant flux). Different types of beam splitters exist, as described in the. I am working on an SPI-based setup where I have one SPI master and four SPI slaves, each connected to the master via their respective Slave Select (SS) lines.