remote-control device. It may be operated by a
control of switching modules to seize and interconnect
dial or automatically pulsed from associated
ship lines and shore lines. The consoles are not much
control circuitry. A 100-point, two-motion switch
larger than standard type G telephone sets and can
can make electrical contact with any of 100 sets
be mounted on a desk or bulkhead, or flush-mounted
of contacts, taking two motions to accomplish
in a suitable panel.
the connection. With the switch mounted in a
horizontal plane, the switch carriage moves first
in the X direction (left to right parallel to the
wire bank), and then in the Y direction (into the
This section explains the fundamentals of XY
wire bank). When mounted in the switchboard,
switching as used in the MDM 200/700 system. It also
the XY switch is located adjacent to a 42- by 10-
describes the operation of the rotary switch that is
wire matrix called a wire bank. This wire bank
used as a selector and the operation of the
runs the length of the switchboard and serves as
switchboard and control cabinets.
the contacts for the wipers of all the XY switches
in the system.
SWITCHING COMPONENTS AND LINE-
FINDING.-- The XY universal switch (fig. 6-29) is
THE XY SWITCH.-- The main components of the
the heart of the MDM system. It provides the means
XY switch (fig. 6-29) are an X-stepping magnet, a Y-
for establishing connections throughout the system.
stepping magnet, a release magnet, spring
The XY universal switch is a 100-point, two-motion,
Figure 6-29.--XY switch.