Description Of Data Mode; Error Handling; Executing Ftp At Command Fails; Pdp Activation Fails - Quectel WCDMA UG FTP Series At Command Manual

5. If module logs in FTPS server successfully, all other operations are the same as FTP client.

1.3. Description of Data Mode

The mode of the COM port includes AT command mode and data mode. The difference between them is
that in AT command mode, the inputted data via COM port will be treated as AT command, while in data
mode, it will be treated as data.
You can exit from data mode by "+++" or pulling up DTR (AT&D1 should be set). To prevent the "+++" from
being misinterpreted as data, it should comply with the following sequence:
Do not input any character in 1 second or longer before inputting "+++".
1)
Input "+++" in 1 second, and no other characters can be input during this time.
2)
Do not input any character in 1 second after "+++" has been inputted.
3)
When you execute AT+QFTPPUT, AT+QFTPGET, AT+QFTPLIST and AT+QFTPNLST, if the local file
path is "COM:", which means data will be received from or output to COM port, the module will enter into
data mode. You can exit from data mode by inputting "+++" or changing DTR level from low to high. Else,
you can reenter data mode by executing ATO command when executing AT+QFTPGET, AT+QFTPLIST
and AT+QFTPNLST. You can't reenter data mode by ATO when executing AT+QFTPPUT.

1.4. Error Handling

1.4.1. Executing FTP AT Command Fails

If you execute FTP AT command and receive response "ERROR" from the module, please check whether
the SIM card is inserted and whether the result of AT+CPIN? is "+CPIN: Ready".

1.4.2. PDP Activation Fails

If you failed to activate PDP context by AT+QIACT command, please check the following aspects:
1. Query whether the PS domain is attached by AT+CGATT? command, if not, execute AT+CGATT=1 to
attach PS domain.
2. Query the CGREG status by AT+CGREG? command and make sure the PS domain has already
been registered.
3. Query the PDP context parameters by AT+QICSGP command, make sure the APN of specified PDP
context has been set.
4. Make sure the specified PDP context ID is neither used by PPP nor activated by AT+CGACT
command.
WCDMA_UGxx_FTP_AT_Commands_Manual
UMTS/HSPA Module Series
WCDMA UGxx FTP AT Commands Manual
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