Internal Control Switches; Carrier Detect (Cd) Signal Options; Factory Setting For Cd / Dcd Or Cd / Sync Switches - Canoga Perkins 2240 User Manual

Canoga Perkins

2.2.2.1 Carrier Detect (CD) Signal Options

There are two switches on the internal switch block which control the response of
the CD signal on the Standard Data Interfaces. These switches operate as a pair
and only one switch should be set to ON at any time.
Factory Setting =
The CD signal may be used as an output for an end-to-end Control Channel by
setting the CD / DCD switch to ON and the CD / SYNC switch to OFF. This
setting is only used with Standard Data Interfaces which do not support the
expanded interface connector.
The factory setting causes the standard data connector CD signal to track the state
of the modem's optical receive synchronizer. CD will assert when the modem is
in local sync. This also means that CD will track the state of the front panel Local
Sync LED.
On expanded data interfaces, the standard data connector CD signal in the CD =
local sync mode (factory setting) can be used to gate CTS (or its equivalent signal)
OFF when the modem's receiver is out of sync. See Figure 2-4 for an illustration
of this factory setting.
Refer to the sections on the RS-449, RS-530, V.35, MC1 and MC2 interfaces for
more information about the CD-CTS gating function.
Rx Fiber
24
CD / DCD set to OFF
CD / SYNC set to ON
RTS from far end
Optical
Receiver
Local Sync
Front Panel LED
J2 = Standard data
connector
CD/DCD
CD
(DCD = RTS from
far end)
or CD/SYNC
To
selector switches
Interfaces
J3 = Expanded data
connector
Figure 2-4.
Factory Setting
for CD / DCD or
CD / SYNC
Switches