&T8 - Local Loopback With Self Test

Command Line Format
AT [cmds] &T8 [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 is configured for analog loopback (low frequency band if none or O suffix is used, high frequency band if A suffix is used). The test timer starts at the time indicated by S18, DSR is turned off (if &S1 is in effect), AL Self-test state is entered, and an OK result code is sent to the DTE. During the test the modem sends a test message and counts errors in the looped back signal.

The test ends when the timer times out (S18) or the &T0, H0, or Zn command is issued. When the test ends, the three-digit error count is sent to the DTE. An OK result code follows the error count.

Result Codes
OK - if AL Self-test state is entered.
OK - after error count is sent to DTE.
ERROR - if any other test is active (&T1, &T3, &T6, &T7), or if in the Online Command State.
Execution Time
Duration of the test and time to send error count to DTE.

DTE Interface Lines Affected
DSR

LEDs Affected
MR flashes

Cross Reference
Commands - &Sn, &T0, &T1, Hn - Control The Switchhook , Zn - Perform Soft Reset
S-registers - S18

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