Switched Configuration Verification - Northern Telecom DMS-100 Series Installation And Maintenance Manual

0 297-2121-226
0 VINTAGE 05.01
0

Switched Configuration Verification

0 Loopback Tests (NT4X25AD /CH /AV /DF)
0 There are three loopback tests:
0 * local loopback
0 * tip-and-ring loopback
0 * far-end loopback
0 The local loopback
0 The DU loops back data at the RS-232C interface towards the
0 Typically, characters entered on the DTE keyboard are echoed back
0 to the DTE.
0 Local (Loc) Loop switch is located on the DU faceplate.
0 1. If the Make Set Busy feature is
0 company,
0 action by pressing the Busy key on the face of the DU.
0 Busy LED lights.
0 of service for testing.
0 2. To perform a local loopback test, set the Loc Loop switch to
0 the Loc Loop position.
0 3. Make sure the DTE power is on,
0 characters
0 DTE keyboard).
0 to the terminal, the connection is good.
0 4. Return the Loc Loop switch to the off position.
0 Test LED turns off.
0 5. Press the
0 Family switch returns the DU to service.
0 The tip-and-ring (T-and-R) loopback test checks the data from the
0 DTE to the tip-and-ring interface at the DU.
0 from the loop and the data is looped back at tip-and-ring inter-
0 face toward the DTE.
0 on the component side of the DU circuit card on SW2, switch posi-
0 tion 4. See
0 switch.
0 1. If the Make Set Busy feature is
0 company,
0 action by pressing the Busy key on the face of the DU.
0 Busy LED lights.
0 of service for testing.
0 5-10
test checks the terminal-to-DU connection.
The Under Test LED lights during the test.
inform the DMS-100
The DMS-100 Family switch places the DU out
The Under Test LED lights.
from the DTE (for example, type characters on the
If the transmitted characters are echoed back
Busy key to turn the Busy LED off.
The T-and-R Loop/Normal switch
Figure 4.6 on page 4-14 for the location of the
inform the DMS-100
The DMS-100 Family switch takes the DU out
assigned by the
Family switch of maintenance
then transmit a
The DU is
assigned by the
Family switch of maintenance
DTE.
The
operating
The
string of
The Under
The DMS-100
isolated
is located
operating
The