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MultiModemZPX User Guide
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
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.
Test procedure
1. Using your communication program, set the baud rate to 9600 and go into ter-
2. Dial the remote modem and establish your online connection.
3. Type the escape sequence +++AT and press E
4. Type AT&T3 and press E
5. Have someone enter data from the remote keyboard. For this test, typing multiple
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 characters received on your monitor
are the same as the characters 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
minal mode. Type AT and press ENTER; you should get an OK message.
online command mode.
dem (if responses are enabled), your modem is placed in digital loopback mode.
uppercase U characters is a good way to send an alternating test pattern of binary
ones and zeros. The data received by your modem enters its analog receiver, is
converted to digital data, is reconverted into analog, and then is transmitted back to
the remote modem. Your modem passes this test if the characters received on the
remote monitor are the same as the characters entered from the remote keyboard.
to exit the test, then type ATO and press
NTER
NTER
. Once you receive an OK message from your mo-
NTER
C Loopback Tests
. This puts the
NTER
to bring your modem into
65
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