Special Features:

19 slots hold up to 16 matrix switching cards (slots 1-16, left to right as viewed from the front), one back up switch card in slot 17, and two control cards in slots 18 and 19; rear of main chassis consists of 16 slots for interface i/o cards, one slot for a termination card, and two half sized slots for the control i/o cards

Properties:

An open or inclosed frame structure designed to accommodate (but does not include) electrical/electronic equipment mounted on standard width panels so that the equipment may be operated after installation without being removed. It must have panel mounting rails that provide a uniform pattern of mounting holes that will accommodate various combinations of standard width panels. It may include wires, cables, terminal boards, connectors, and the like, required for equipment operation. See also mounting base, electrical equipment; cabinet, electrical equipment; and case (2) (as modified). Excludes main distributing frame, telephone and intermediate distributing frame, telephone.