The Step-Pak™ SPI-8 Indexer Module is an 8 Channel indexer/controller that plugs into the SPR-9 Step-Pak Equipment Rack. The controller provides step and direction input for up to 8 stepping motor drive modules plugged into the Step-Pak enclosure. Home, Limit + and Limit - inputs are available for each channel. The SPI-8 also supports 8 status and eight control outputs available via front panel connectors. Communications with the host computer is via RS-232 or RS-485 communications ports. Messages and asynchronous ASCII characters. Driver status outputs are also monitored with the SPI-8. Status level is Hi when normal, and goes Low when a particular module is not plugged in, or a motor is switched off by a front panel switch, or the power supply is not present.