1 year, 6 months ago.

Why is the C030-N211 board running with a wrong AT Command but not without it?

Hello everyone,

I've got a problem with the C030-N211 NB-IoT board. I'm trying to implement a simple ping pong with the board as the device and a local UDP server.

I am using a 1NCE SIM card and the mbedOS library, especially the ATCmdParser, to work with the AT commands.

The tests of my implementation have been successful and I was able to communicate with the server and vice versa using the following AT command:

AT command in line 4 is wrong but still needed

//initalizing network settings

//checking if connection has been established

//creating a socket and sending a UDP message

This was successful and I was able to send and receive messages. But when cleaning up my code I realized that I had a spelling mistake in the third AT command ("AT+CFDCONT" instead of "AT+CGDCONT"). I corrected this and tested the implementation once again and realized that it was not working anymore.

After multiple test, e.g. sending absolut nonsense as an AT command, I came to the conclusion that a "wrong" command is required between CFUN and NBAND to get the code to work which is kind of strange behavior.

Does anyone have an idea what I am doing wrong or where this behavior may come from?

If some more informations, e.g. code, are needed I will try to give them if requested.



Be the first to answer this question.