Backplane for a modularly expandable programmable controller

摘要

A modular programmable controller having an expansible backplane formed of a plurality of structually and electrically connectable backplane units, each comprising a housing having at least a pair of side walls, corresponding edges of which define a seating surface against which an input/output module may be secured. Between the side walls are located field wiring and control bus connectors which allow plug in and removal of a module without disturbing the field wiring or control bus. The control bus segment in a backplane unit comprises an edge card receiving connector in one side wall connected to a card with conductors protruding from the other side wall, the card also being connected to a control bus connector for the module.