Black Box 32144, Manual

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MODEM 32144
Fig. 7-5. Digital Loopback (DLB) Test.
DATA TERMINAL EQUIPMENT
(DTE) AT LOCAL SITE
REMOTE
MODEM
RECEIVER
LOCAL MODEM
TRANSMITTER
RECEIVER
TRANSMITTER
In Hayes mode only, the DLB test
can be initiated using the
command &T3 (preceded by AT).
In any mode, the DLB test can be
initiated using the modem’s front-
panel controls, as follows:
From screen 2 of the LCD MAIN
MENU, select TEST. Go to screen 2
of the LOCAL TEST menu and
select DLB.
The DIGITAL LOOPBACK
screen will be displayed, with ON
and OFF as the possible selections.
Select ON to activate the test. The
EIA status screen will be displayed
while the test is being conducted.
Make sure that test data is being
generated. Watch for data errors.
By transmitting test data and
comparing it with the received
copy, the DTE is checked for
proper operation. To end the
test, press the ENT pushbutton
to return to the DIGITAL
LOOPBACK screen, and then
select OFF.