Switch From Data Mode To Command Mode - Quectel M35 Command Manual

Reference
V.25ter
Parameter
<n> 0
NOTE
OK is issued after circuit 109(DCD) is turned off, if it was previously on.

7.4. +++ Switch From Data Mode to Command Mode

+++ Switch From Data Mode to Command Mode
Execution Command
+++
Reference
V.25ter
NOTES
1. To prevent the "+++" escape sequence from being misinterpreted as data, it should comply to
following sequence:
No characters entered for T1 time (0.5 seconds).

 "+++" characters entered with no characters in between. For CSD call or PPP online mode, the
interval between two "+" MUST should be less than 1 second and for a transparent TCPIP
connection, the interval MUST should be less than 20 ms.
 No characters entered for T1 time (0.5 seconds).
 Switch to command mode, otherwise go to step 1.
2. To return from command mode back to data or PPP online mode: Enter ATO
 Another way to change to command mode is through DTR, see AT&D command for the details.
M35_AT_Commands_Manual
Disconnect from line and terminate call
Response
This command is only available during TA is in data mode,
such as, a CSD call, a GPRS connection and a transparent
TCPIP connection. The "+++" character sequence causes the
TA to cancel the data flow over the AT interface and switch to
command mode. This allows you to enter AT command while
maintaining the data connection with the remote server or,
accordingly, the GPRS connection.
OK
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