Power supply arrangement for fault-tolerant operation in a microcomputer-based encryption system

摘要

An improved fault-tolerant arrangement for use in a multichannel data encryption unit is disclosed. In accordance with the teachings of this invention, a data encryption system includes a plurality of data encryption devices and a host computer and display system wherein a data bus which couples the host computer and data encryption devices includes first and second power supply lines. Each of the respective data encryption devices includes means for automatically deriving power from either of the first or second power supply lines based on the presence of power thereon. Accordingly, fault-tolerant operation is provided wherein the respective data encryption devices continue operating even in the event of the failure of the host computer.