Chapter 2 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (S000273G) 27
Automated system that needs to periodically use the line while giving the voice
user the highest priority
A common use for these features: An automated system that needs to periodically use the
line while giving the voice user the highest priority. The automated system makes a
connection when the line is free. It does this without disturbing the line if the line is in use.
The automated system periodically retries the connection until the line is free.
Once free, it dials and makes its connection. If a voice user wishes to use the line while
the modem is connected. the modem drops the line and gives it to the user. The modem
will then try to regain control of the line by once again periodically retrying to establish a
connection.
AT-STE=7
OK
ATDT5551212
CONNECT
Sometime later, the user picks up phone
NO CARRIER
ATS86?
25
OK
Delay 30 seconds
ATDT5551212
LINE-IN-USE
Try again some time later user hangs up the phone
CONNECT
Command: &Tn V.54 Test Command
Values: n = 0, 1, 8
Default: None
Description: The modem can perform selected test and diagnostic functions. A test can be run only
when the modem is in asynchronous operation in non-error-correction mode (normal or
direct mode). To terminate a test in progress, the escape sequence (+++) must be entered
first.
&T0 Abort. Stop any test in progress.
&T1 Start local analog loopback, V.54 Loop 3. If a connection exists when this
command is issued, the modem hangs up. A CONNECT message is displayed at
the start of the test.
&T8 Starts local analog loopback, V.54 Loop 3, with self-test. If a connection exists, the
modem hangs up before the test begins. When the test is terminated, the number
of detected errors is reported to the computer.