Comtrol AT Commands - Manual (Page 81)

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
102184B Conexant 3-55
Automated system that needs to periodically use the line while giving the voice user the highest priority
A common use for these features would be an automated system that needs to
periodically use the line while giving the voice user the highest priority.
The automated system would make a connection when the line is free. It would do this
without disturbing the line if the line is in use. The automated system would periodically
retry the connection until the line is free. Once the line is free it would dial and make its
connection. If a voice user wishes to use the line while the modem is connected. The
modem will drop the line and give the line 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
-TRV – Tip & Ring Voltage
This command allows the host to read the voltage that the modem sees across Tip &
Ring.
Syntax
-TRV
Example
Command: AT-TRV
Response: 1.4
Note: The voltage measurement is read on the opposite of the diode bridge, so the
modem assumes and compensates for the voltage drop across 2 diodes. Therefore, if no
line is connected, the modem will report 1.4V.