User`s guide

Test Mode Operation
7-2 Modem 3600
Note
These tests do not apply to fax mode and should only be
performed when the modem is configured for data operation.
LDL, RDL, and RDL/TP tests are initiated after making an online data
connection in normal or direct mode only. LAL and LAL/TP are
initiated while in offline command mode. These tests can be initiated by
AT commands or by using the LCD front panel SELECT TEST menus.
Refer to Table 7-2.
Note
Bold text indicates command parameter defaults.
Terminating a Test in Progress &T
Tests can be terminated manually or automatically. The &T command
terminates a test manually. The modem automatically goes to command
mode during LDL, LAL/TP, and RDL/TP tests. Enter the &T command
to terminate the tests. For LAL and RDL, enter the escape sequence
(+++) before the &T command to go to the command mode.
By preloading register S18 with 1 to 255, each test mode automatically
times out after the specified number of seconds and exits back to the
command mode. Loading S18 with 0 disables the auto timeout feature
and the test will run continuously until manually terminated.
Table 7-2. Test Commands
Command Operation
&T Terminate any test
&T1 Initiate local analog loopback test
&T3 Initiate local digital loopback test
&T4 Grant remote requested digital loopback
&T5 Deny remote requested digital loopback
&T6 Initiate remote digital loopback test
&T7 Initiate remote digital loopback with test pattern
&T8 Initiate local analog loopback test with test pattern
%T Transmit test pattern