Get the number of ACK attempts

[kkhylchuk]

Hi,

For enabled ACKs dot->setAck(8); is there a way to get the number of attempts to receive an ACK?

Thanks.

[Jason Reiss]

See getAck in the header file to retrieve the value that is set.
https://github.com/MultiTechSystems/libxDot-dev/blob/master/mDot.h

There are events for missed ACK that shows number of retries, and PacketRx gives the number of total retries when ACK is received.
https://github.com/MultiTechSystems/libxDot-dev/blob/master/mDotEvent.h

[kkhylchuk]

Thanks, Jason.

I implemented mDotEvent::MissedAck, but for some reason “retries” is always 0. I expected it to be equal to dot->getAck(). Or am I understanding this wrong?

[Jason Reiss]

MissedAck retries should be the current number of retries attempted.

If you miss the first ACK is should be 0
If you miss the second ACK is should be 1
…

[kkhylchuk]

Yes, that’s what I expected to see, but instead, I see this:

...
[INFO] Preparing frame
[INFO] Adjust PowerMax to 21
[INFO] Configure radio for TX
[INFO] Rx Window 1
[DEBUG] mDotEvent - MissedAck : retries 0
[INFO] Rx Window 2
[DEBUG] mDotEvent - MissedAck : retries 0
[ERROR] ACK not received
[ERROR] failed to send data to gateway [-5][Operation Timed Out]
[INFO] Preparing frame
[INFO] Adjust PowerMax to 21
[INFO] Configure radio for TX
[INFO] Rx Window 1
[DEBUG] mDotEvent - MissedAck : retries 0
[INFO] Rx Window 2
[DEBUG] mDotEvent - MissedAck : retries 0
[ERROR] ACK not received
[ERROR] failed to send data to gateway [-5][Operation Timed Out]
...

I set the ACK retries to 8 like so dot->setAck(8).
Calling dot->getAck() returns 8.

Also, I should note that I’m using libmDot-dev v4.1.2.

[Jason Reiss]

What channel plan are you using?
Do you have ADR enabled?

In LoRaWAN 1.0.4 the network controls the number of retries when ADR is enabled.
Perhaps the settings is being overridden by an ADR MAC Command?

You could try to call setACK before each send.

What LoRaWAN network are you communicating with?

[kkhylchuk]

Channel Plan: US915
ADR is enabled
MultiTech’s Conduit, public network

Indeed, I see incoming ADR commands:

[DEBUG] ADR Set Redundancy 1
[DEBUG] ADR DR: 0 PWR: 0 Ctrl: 07 Mask: 0002 NbRep: 1 Stat: 07
[DEBUG] ADR Set Redundancy 1
[DEBUG] ADR DR: 0 PWR: 0 Ctrl: 00 Mask: ff00 NbRep: 1 Stat: 07

I tried calling setAck before each send, but no luck. The result is exactly the same.

• This reply was modified 2 years, 3 months ago by kkhylchuk.
• This reply was modified 2 years, 3 months ago by kkhylchuk.

[SaSa]

do you know please how I should put Rx Window = 1 in a downlink message ?

[Jason Reiss]

A downlink can be queued through MQTT, rx_wnd is one of the parameters.

https://www.multitech.net/developer/software/lora/lora-network-server/mqtt-messages/

[Author]

Posts