Segmented messages and access_model_publish()

RE: Segmented messages and access_model_publish()

Amadeus — Thu, 05 Dec 2019 15:13:00 GMT

Hi,

I am aware of that. As I said above, I am starting an event (and logging) at the receiver when he receives the message, so there are no ongoing messages when I get the error. My messages are between 15-30 bytes, which should not take 1,4 seconds anyways.

After changing the parameters as in the ticket you referred to, I am able to resend messages much faster. But I am curious to know what implications these changes may cause and what they affect.

RE: Segmented messages and access_model_publish()

Joakim Jakobsen — Thu, 05 Dec 2019 14:18:16 GMT

What kind of message are you sending back and forth?

If the message payload is larger than 11 bytes, the packet will be segmented and it would take longer time to reach to the destination.

RE: Segmented messages and access_model_publish()

Amadeus — Tue, 26 Nov 2019 14:19:47 GMT

Yes, the issue I am referring to is that I get a mesh error if I, from the same device, sends two unacknowledged messages with an interval of less than about 1,4 seconds. I do not understand why this mesh error occur, neither do I understand why tweaking the parameters referred to above helps.

Changing the parameters have not caused any deviation in functionality compared to before as far as I can see, and as long as I can keep them this way without fearing any problems in other parts of the code, I certainly will. However, I am curious to know what's causing the mesh error with the default parameters.

RE: Segmented messages and access_model_publish()

Joakim Jakobsen — Tue, 26 Nov 2019 14:12:50 GMT

Hi again.

[quote user="Amadeus"]So, what could this issue come from?[/quote]

What issue are you referring to here?

[quote user="Amadeus"]Can I leave the parameters as it is now?[/quote]

If it is working without any errors, I don't see any reason that you couldn't use them. But you did refer to an issue (quote above)?

- Joakim

RE: Segmented messages and access_model_publish()

Amadeus — Tue, 26 Nov 2019 12:10:57 GMT

Hi, Joakim,

Indeed, my issues are very similar to the ticket you are referring to, and my mesh error originates from packet_tx() in access.c.

I tried to change the parameters in a similar way as the guy in the ticket you are referring to, and now I am able to send consecutive unacknowledged messages in a much shorter interval than with the original parameters. Before, as I said earlier (which was a bad explanation), I could send consecutive unacknowledged messages from the same device/element approximately every 1400 ticks, that is 1,4 seconds, without getting the mesh error. Now I am able to send consecutive unacknowledged messages much faster. near 200 ticks (0,2 seconds) before the mesh error occurs.

I know that the message I am sending is sent because I am starting an event at the other device when it receives the message. Therefore, it should not be several segmented messages ongoing at the same time.

So, what could this issue come from? Can I leave the parameters as it is now? I.e., TRANSPORT_SAR_TX_RETRY_BASE_TIMEOUT_DEFAULT_US MS_TO_US(200) and TRANSPORT_SAR_TX_RETRIES_DEFAULT (2)? Or could that cause any problems later?

RE: Segmented messages and access_model_publish()

Joakim Jakobsen — Tue, 26 Nov 2019 09:22:06 GMT

Hi.

Have you been able to track down where the Mesh error 8 (NRF_ERROR_INVALID_STATE) originates from?

Maybe you can take a look at this previous ticket, and the suggestions from my colleague Hung?
https://devzone.nordicsemi.com/f/nordic-q-a/51653/mesh-network/
This ticket seems to have some similarities to your issue.

Best regards,
Joakim