Northern Telecom DMS-100 Series Installation And Maintenance Manual page 96

0 297-2121-226
0 VINTAGE 05.01
0 9. Press the Alternate key.
0 To Perform a Local Loopback Test:
0 1. Press the Settings key.
0 2. Press the Alternate key.
0 3. Press the
0 lights.
0 4. Press the Settings key again.
0 the Under Test LED lights.
0 5. Make sure the DTE power is on, then type a string of
0 ters on the DTE keyboard.
0 back to the terminal, the DTE to DU connection is good.
0 6. Press the Settings key.
0 7. Press the
0 turns off.
0 8. Press the Settings key.
0 turn off.
0 9. Press the Alternate key.
0 The far-end
0 The data is looped back at the DTE interface of
0 toward the
0 echoed back to the DTE.
0 To Perform a Far-end Loopback Test::
0 /AZ)
0 1. Set the Far-end Loop/Normal option switch, located under the
0 flip-up lid, to the Far-end Loop position.
0 LED lights.
0 2. Setup a call to another DU.
0 3. Type a
0 typed characters are echoed back to the terminal, the end-to-
0 end data channel is good.
0 4. Take down the call.
0 5. Return the Far-end Loop/Normal switch to the Normal position.
0 The Under Test LED turns off.
0 5-6
The Settings LED lights.
3 on the numeric
The Settings LED lights.
3 on the numeric keypad.
loopback test
near DU. Characters entered on the DTE keyboard are
string of characters on the DTE keyboard.
The Alternate LED turns off.
(NT4X25AG /AK)
The Alternate LED lights.
keypad.
The Settings LED turns off and
If the typed characters are echoed
The Local Loopback LED
The Settings and
The Alternate LED turns off.
checks the end-to-end data channel.
(NT4X25AA /AE /AN
The Local Loop LED
charac-
Under Test LEDs
the far-end DU
/AP /AX
The Under Test
If the