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MultiModemII User Guide
2. Open your communications software and go into terminal mode. Type AT and
3. Dial the remote modem and establish your online connection.
4. Type the escape sequence +++AT and press E
5. Type AT&T6 and press E
6. Enter data from your keyboard. For this test, typing multiple uppercase U char-
7. To exit the test, type the escape sequence +++AT and press E
Note: You can also start and stop a remote digital loopback test by using the front
panel LCD and buttons. See "Diagnostic Options Trunk" in Chapter 3.
Local Digital Loopback Test (V.54 Loop 2)
The local digital loopback test is identical to the remote digital loopback test with
one exception. Instead of using your modem to signal a remote modem to place it-
self in digital loopback mode, your modem is placed in digital loopback mode while
the remote modem is not. Data is entered and transmitted from the remote modem,
sent across the phone line to your modem, and looped back to the remote modem.
Figure C-3. Local digital loopback test.
press E
; you should get an OK message. Type AT\N and press E
NTER
disable error correction. Type AT+MS=9,1,9600,9600 and press E
local modem to V.32 mode at 9600 bps.
online command mode.
transmitting an unscrambled marking signal, which causes the remote modem
to place itself in digital loopback mode. Then the local modem exits online com-
mand mode and enters data mode.
acters is a good way to send an alternating test pattern of binary ones and zeroes.
Data received by the remote modem enters its analog receiver, is converted to
digital data, is reconverted into analog, and then is transmitted back to your
modem. Your modem passes this test if the data received on your monitor is the
same as the data entered from your keyboard.
modem in online command mode. The modem should respond with an OK mes-
sage. If you wish to stay on line with the remote modem for normal data trans-
mission, type AT&T and press E
E
to return on line. If you wish to terminate the call, type ATH and press
NTER
E
to hang up.
NTER
NTER
. The local modem responds to this command by
NTER
to exit the test, then type ATO and press
NTER
C Loopback Tests
NTER
to set the
NTER
to bring your modem into
. This puts the
NTER
to
89
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