What is in Ant Acknowledgment message coming from the receiving node

[Paul]

We all know we can send acknowledged data in Ant channel.

But based on my test. the acknowledgement message coming back to the originating device is just a dumb packet. It doesn't include a hash code or message id to identify what it is acknowledging for.

This is my test. One unit as a master, Open a master channel Two units as slave, Open a slave channel. Frequency: 0.5HZ. After two slave units are tracking to the master, I will trigger both sending different acknowledged data to the master at the same time (with 0.5HZ, it is easy to control that). Obviously one will fail or both will fail because both RF transmission are in the air at the same time. But interesting thing is, when there is one succeeded, the other slave will receive the EVENT_TRANSFER_TX_COMPLETED event too! I was expecting a EVENT_TRANSFER_TX_FAILED.

Anybody with better or deeper understanding of the acknowledgement message please clarify this.

Thanks

Paul

[Paul]

Basically what I am saying is EVENT_TRANSFER_TX_COMPLETED event doesn't guarantee the message got delivered correctly. I hope I was wrong, or my code had a bug. Keep testing :-)

[Asbjørn]

You have configured two slaves with same address talking to the same master on the same ANT channel. The ACK will be interpreted by both slaves as their ACK. You should either use a shared channel and no ACKs or open a separate channel for each slave with their own ACKs.

[Paul]

Thanks Asbjorn. Understood I should use different configuration for my application. I just wanted to confirm that the same ACK could be interpreted by different slaves and trigger EVENT_TRANSFER_TX_COMPLETED. My next attempt will be: is there anything useful and accessible inside the ACK coming back could be used to tell if this ACK is actually initiated by MY acknowledged broadcasting?

[Asbjørn]

Not unless you use payload in the ACK. Then you could is that payload to identify which of them that actually ACKed.