PURPOSE AND FUNCTION OF EQUIPMENT
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
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