I have set the end device to acknowledgement mode, i.e. at+cfm=1, but after each uplink of data, I only see that the gateway receives the data. I don’t see downlink ack in the end device packet capture at the gateway, and I don’t see any downlink ack in the end device at+recv=? Nothing is received either, only at+recv=0: is displayed. Is there something wrong with my settings and how should I set it up to see if the terminal is receiving the ack?
+EVT:SEND_CONFIRMED_OK is the message that tells you that the packet was acknowledged by the server.
+EVT: SEND_CONFIRMED_FAILED is the message when no ACK was received.
As you are running a custom application it would be even better to initialize the TX callback. There you can get this information as well.
The ACK is an empty packet, so AT+RECV cannot show you anything.
Okay, thank you very much for your answer.