TM 11-7025-234-23
TECHNICAL PRINCIPLES OF OPERATION
This chapter explains how the V.29 modem works., and how it interfaces with
transmission lines to send and receive data.
2-2. OPERATING PRINCIPLES
The V.29 modem normally operates unattended except for normal monitoring of
indicator lamps. Each local and remote modem is automatically synchronized if
output rate quality degrades during operation. The input and output data rate is
normally 9600 bps. It is possible for the unit to switch down automatically to a
lower rate if degradation does occur. Start up is accomplished by the operator
using controls on the front panel.
All operating controls and indicators are accessible from the front of the modem
test switches is obtained by lowering the front panel.
a. Mother Board Controls. The mother board controls and indicators are located
at the bottom of the front panel and are shown and described in figure 2-2.
b. Front Panel Controls and Indicators. The controls and indicators for the
different boards are found on the edqes of the boards and protrude through slotted
locations on the front panel (fig. 2-3).
Front Panel
