Issues with Transparent mode on the EC21

I am connected to my Quectel EC21 over UART. I have been sending it commands to setup TCP connections in transparent mode. However, it is very inconsistent and regularly sends the “NO CARRIER” message despite having a strong 4G connection. It often sends “NO CARRIER” in response to the first message I send to the server.

Any pointers on how to fix this would be much appreciated.

Hi @charlieR
Can you use the AT+QENG=“SERVINGCELL” command to query the network status? And take a screenshot.

Thank you for your response. The response to the serving cell command is:

+QENG: “servingcell”,“NOCONN”,“LTE”,“FDD”,234,15,219D22,290,323,1,4,4,1806,-95,-12,-62,3,29


@lyman-Q Does the above message help diagnose the issue?