Intel MD566X - Manual (Page 38)

56K V.92 Data, Fax, and Voice Chipset
38 Intel Confidential Programmer’s Guide
3.9.2 Local Analog Loopback With Self-Test [AT&T8]
This test is used by the local DTE to check the DTE-to-modem communication integrity.
Figure 3-3. Local Analog Loopback with Self-Test
Local Modem (or Test Modem)
AT&F &W Returns the modem to the factory de-
faults.
AT S18=20 &T8 Causes the modem to start local analog
loopback with self-test for 20 sec-
onds.
OK After starting analog loopback, the mo-
dem goes back to command mode.
AT The modem responds to new commands.
OK
000 After 20 seconds, the modem stops ana-
log loopback, sends
OK An error count to the DTE, and enters
command mode.
AT S18=0 &T8 Causes the modem to start local analog
loopback with self-test, which is only
terminated by AT&T0 or ATH.
OK After starting analog loopback, the mo-
dem goes back to command mode.
AT The modem responds to new commands.
OK
AT&T0 After receiving AT&T0 or ATH, the modem
stops analog
000 loopback, sends an error count to the
DTE, and enters
DTE
TXD
RXD
TRANSMITTER
RECEIVER
LOCAL MODEM
PATTERN
GENERATOR
PATTERN
CHECKER