PURPOSE AND FUNCTION OF EQUIPMENT

11-5805-451-15

The Express Orderwire Multidirection Unit, shown in figure l-l, provides

facilities for multipoint conference connection of the express orderwire circuits while

maintaining separation between the transmit and receive legs of the circuits.

The interconnections are accomplished in four-way, four-wire hybrids, and

associated amplifiers and attenuators are used to provide the gains and losses

required to match external circuit level requirements. The Express Orderwire

Multidirection Unit allows construction of a multipoint, four-wire orderwire

circuit with all users having full-time talk and receive capability. Strapping

options of the Express Orderwire Multidirection Unit allow the Express Order-

wire Unit to be connected to as many as nine voice-frequency (VF) paths and/or

radio circuits.

1.3 PHYSICAL DESCRIPTION

The Express Orderwire Multidirection Unit is a solid-state device, designed

for mounting in a standard 19-inch equipment rack. The unit consists of a metal

mounting shelf equipped with as many as 17 plug-in printed wiring board assemblies.

A hinged cover plate is installed on the front of the unit. See figure 1-2.

The unit is approximately 3-1/2 inches high, 19 inches wide, and 12-1/4

inches deep. The assembly weighs approximately 8 pounds when equipped with a

full complement of plug-in assemblies. All input and output signal connections

are made to solderless terminals on barrier-type terminal strips at the rear of

the unit. The unit contains no mechanical assemblies and therefore requires no

lubrication.