We are using TRB142 to transfer data via COM port to a remote FTP server. The procedure to upload data ican be read in "EC2xEG9x&EM05_FTP(S)_AT_Commands Manual" from Quectel. Basically, you setup the TRB142 as a FTP client via a set of AT commands. After AT+QFTPPUT, the TRB142 switches to data mode and accepts data from the COM-port. To end data mode, one should send "+++" via the COM port.
That, however, doesn't work. There is really no way to exit data mode which means you can't close the connection from the TRB142. After a timeout period - typically a few minutes, the remote FTP server aborts the connection. But this is not the way it's supposed to work.
Comments appreciated. Anyone having the same issue?