Discuss about issue in EC200U- CN module. Data sending over TCP server

IoT Modules LTE Standard Module
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1

  1. I used the following commands to send data continuously to the TCP server:
    a) AT
    b) AT+QIACT=1
    c) AT+QIOPEN=1,0,“TCP”,“35.239.174.234”,2119,0,2
    d) HELLO_TC — Data to be sent

  2. I was able to send data successfully two times, and I also received responses from the server.

  3. However, the problem occurs during the third transmission: when I send data, the response is “NO CARRIER”.

  4. Since this is transparent mode, I don’t understand why this is happening.

  5. In transparent mode, AT commands are not required for each data transmission, so ideally this issue should not occur.
    Please suggest solution for this. OR any another option for this

2

hi，
Thank you for your detailed description.
In transparent transmission mode, AT commands cannot be executed. If the socket connection is disconnected due to a network error or other reasons, the module will report “NO CARRIER”.
Please provide the return value of AT+QGMR and the AT log.

3

a) AT
b) AT+QIACT=1
c) AT+QIOPEN=1,0,“TCP”,“35.239.174.234”,2119,0,1
d) AT+QISWTMD = 0,2
d) HELLO_TC — Data to be sent

Result Log:
RDY

+CFUN: 1

+CPIN: READY

+QUSIM: 1

+QIND: SMS DONE

+QIND: PB DONE

OK

OK

OK

+QIOPEN: 0,0

CONNECT
IGELTUU¸¿mB Ý,D€êê‚ꀤñéÑ‘ðõ€<¿õ€0½ð‘?ôØ®Oð_êÜ ¿2_êÜ ¿2ëÜÂñ IGELTUU¸¿mB Ý,D€êê‚ꀤñéÑ‘ðõ€<¿õ€0½ð‘?ôØ®Oð_êÜ ¿2_êÜ ¿2ëÜÂñ 
NO CARRIER

OK

+QIOPEN: 0,563

ERROR

4

Hello AnnaLiu,
Any update on our issue. Please inform us as soon as possible.

5

Hello AnnaLiu,
Any update on our issue. Please inform us as soon as possible.

6

hi

Sorry for the late reply.
I sent you a private document for your reference.

Thanks

7

Quectel_EC200U&EG915U_Series_TCP(IP)_Application_Note_V1.1.pdf (462.7 KB)
We are using this document. Are these two documents the same, or is there any difference between them?

8

hi ,

Error 563 is reported because the socket identity is already in use.
Please execute AT+QICLOSE=0 and then retest.

9

Hi,
Where exactly is the AT+QICLOSE=0 command used? Could you please share the list of commands that are useful for sending data continuously over a TCP server?

10

This command is used to close the TCP connection. There are instructions on the AT document.