Switch From Command Mode To Data Mode; Use Ato To Switch From Command Mode To Data Mode; Terminate The Connection - Quectel UC20 Application Note

UMTS/HSPA Module Series
UC20 PPP Application Note
NOTE
Please make sure above operation is operated after completion of PPP negotiation. If not, above
operation will terminate the PPP negotiation and quit from data mode. When UART/USB is changed to
command mode after accomplishing PPP negotiation, the data will be treated as AT command and
module still remains PPP connection.

4.1.2. Switch from Command Mode to Data Mode

4.1.2.1. Use ATO to Switch from Command Mode to Data Mode

Example
//When PPP connection exists, and module is in command mode.
ATO
CONNECT 14400000 //Indicates that TA has entered into data mode; inputting
commands from UART will be treated as PPP data.

4.2. Terminate the Connection

It is recommended to terminate the connection with LCP Terminate-Request message in PPP. This
method must be operated in data mode.
TA can also terminate the connection by switching the DTR level. You should set DTR function with
AT&D2 first. This method must be operated in data mode as well.
Example
//Module is still in command mode before PPP connection has been set.
AT&D2
OK
When PPP connection exists already, switch the DTR level from low to high, the data connection will
terminate automatically. Module enters into command mode after PPP connection is terminated
completely.
UC20_PPP_Application_Note Confidential / Released 12 / 29