I noticed that whenever I send CNF uplink, I receive a downlink with the same port as uplink but no data. Is that expected? I thought downlink will be sent if it is queued by user/app.
I am using Microchip mote RN2903 with RisingHF conecentrator (RHF0M301).
Thanks for your reply.
Noted on limit of daily uplinks. I was not aware of this limit and probably have sent quite a number of uplinks while testing.
As for the downlink that i am receiving, it seems it is not ACK. Below is what the tx command response for the mote I am using. I am getting "mac_rx " for the confirmed uplinks and the port number is usually the same as tx port number. So, it looks really the downlink without data.
Response after the uplink transmission:
• mac_tx_ok if uplink transmission was successful and no downlink data was
received back from the server;
• mac_rx if transmission was successful, : port
number, from 1 to 223; : hexadecimal value that was received from the
server;
The third ACK frame in this example also carries an application payload. A downlink frame can carry any combination of ACK, MAC control commands and payload.