Slots 1-17 can be filled with VSI blade products such as the AVN220 encoder. The PSA200 power supplies are used in slots 18 and 20 to power the platform. Use one PSA200 or add an optional second PSA200 for dual redundant power supply support. The MPP1700 is designed to be mounted in a standard 19 inch rack and to be oriented such that the card insertion, cabling and indicators are facing out the front of the rack. Only the AC power connection is located on the back of the unit.