Digicom Leonardo 33.6, User Manual

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LEONARDO 56
Diagnostic
4.1
4. DIAGNOSTIC
This modem has a very powerful command set and facilities to test the modem
itself, the telephone line and the remote side.
In this chapter you can find some simple procedures to implement the
diagnostic features.
IMPORTANT
To activate the loop the modem must be set up without error correction (AT\N0).
4.1. LOCAL ANALOG LOOPBACK TEST (CCITT LOOP 3)
The target of this test is to verify the modem itself. When the modem is Off
Line type the command: AT&T1.
This command forces the modem in local analog loop that means to be
connected with itself. You can send single or characters strings or files and
they are received from your computer. To exit from test condition type the
escape sequence (+++) and then, when the response OK is displayed enter
the command AT&T0.
4.2. LOCAL DIGITAL LOOPBACK TEST (CCITT LOOP 2 LOCAL)
The target of this test is to verify the COM port and the serial cable of your
computer. When the modem is Off Line type the command: AT&T3.
This command forces the modem in local digital loop that means to connect
send data and receive data before modulation processor.
You can send single or characters strings or files and they are received from
your computer. To exit from test condition type the escape sequence (+++)
and then, when the response OK is displayed enter the command AT&T0.
4.3. LOCAL ANALOG LOOPBACK WITH SELFTEST
The target of this test is to verify the modem itself using an internal test
pattern When the modem is Off Line type the command: AT&T8.
This command forces the modem in local analog loop, sends a test pattern
and check the receive stream. The duration of this test is defined from register
S18.