2.3.4.5.1 Modems That Recognize Local Loop
If your modem recognizes the
loopback signal, perform the following steps:
TEST DATA_LOOPBACK/CH
n/LOCAL
Replace n with the number of the port (0, 1, 2, or 3). If the test fails, go to
Section 2.3.5. If this test succeeds, reset the modem and then test the remote
link.
NOTE
Some modems have more than one test facility. You can use these
additional tests to run more extensive tests on the modem. Refer to
the manufacturer’s instructions for information on any further test
facilities.
2.3.4.5.2 Manually Controlled Modems
If the modem has a manual test
facility, perform the following steps:
1.
Switch the modem so that it loops data back (refer to the manufacturer’s
instructions).
2.
Enter the command:
TEST DATA_LOOPBACK/CH
n/MANUAL
Replace n with the number of the port (0, 1, 2, or 3).
If the test fails, go to Section 2.3.5. If this test succeeds, reset the modem and
then test the remote link.
2.3.4.5.3 Modems with No Test Facilities
If your modem does not have
built-in test facilities, perform the following steps:
1.
Detach the communications link from the modem.
2.
Attach a suitable loopback connector to the modem.
3.
Enter the following command at the console:
TEST DATA_LOOPBACK/CH
n
Replace n with the number of the port (0, 1, 2, or 3).
If the test fails, go to Section 2.3.5. If this test succeeds, reconnect the
communications link and test the remote link.
Using Loopback Tests 2–15
