&T1 - Initiate Local Analog Loopback

Command Line Format
AT [cmds] &T1 [suffix]<CR>

Suffix Values
O or A

Default
N/A

Stored by &Wn
N/A

Displayed by &V
N/A

Description
The modem goes on hook and configures itself for analog loopback (using low frequency band if no suffix or O suffix, or high frequency band if a suffix). DSR is turned off (if &S1 is in effect), the analog loopback state is entered, and the test timer is set to the value in S18. A CONNECT result code is sent to the DTE, and the test timer then begins its count down.

The test terminates when the test timer expires. If S18 equals 0, then the test can only be terminated by escaping from the online state into the Online Command State and sending an &T0, H0, or Zn command; or by a DTR on-to-off transition under certain conditions. See Basic Modem Operation.

While any command may be entered while the modem is in this test state, the modem response is not specified except for H0, &T0, and Zn. These commands terminate the test.

Upon termination of the test, the modem reverts to the Idle State. The command is only valid in the Idle State.

Result Codes
CONNECT - when local analog loopback state is entered.

OK - after test is stopped by either the test timer, the H0 command, or the &T0 command.

ERROR - if other &Tn tests are active (except &T0) or if in the Online Command State.

Execution Time
Determined by test timer or until aborted by a command.

DTE Interface Lines Affected
DSR

LEDs Affected
MR flashes

Cross Reference
Commands - &Sn, &T0, &T8, Hn - Control The Switchhook , Zn - Perform Soft Reset
S-registers - S18

DTE signals - DSR

LEDs - MR

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