Questions about ESB tx_payload.noack

[Lurn_Z]

Hi all,

I want to konw the tx_payload.noack means.

In this link, your colleague said that when the .selective_auto_ack = true, then .noack will work. But didn't say much about it.

And this link, your colleague said that  If you set .noack to 0, then there is no retransmit (and only 1 attempt). 

My question is:

1. In my program, the .selective_auto_ack = false, will .noack work? if .noack is not in effect, how many times will I send data? (e.g.  the .retransmit_count = 3)

2. How should I set to make .retransmit_count effective? And how should I set about the .noack?

  What I want is that when I receive the data it doesn't need to retransmit more times. But if I don't receive data, it should retransmit up to three times until I receive it.When the number of retransmissions reaches three times, it will not retransmit.

3. If there is no ACK, will it affect me sending data from RX to TX after received TX data?

    Because some times I need send control commands from PRX to PTX.

The SDK is 17.1.0.

Any help or suggestion is appreciated!

Best regards

Lurn

[Lurn_Z]

Do you have a good explanation for the above question?

[Lurn_Z]

Is there anyone who can give me some advice?

I have verified the third question, .selective_auto_ack = false, neither .noack=true/false will affect PRX send packet to PTX.

[Sigurd]

Hi,

Lurn_Z said:

1. In my program, the .selective_auto_ack = false, will .noack work? if .noack is not in effect, how many times will I send data? (e.g.  the .retransmit_count = 3)

 

The selective_auto_ack feature allows you to use the "no ack" feature, so that you can disable ACK's on some packets. Without this feature enabled you will receive ACK on all packets.

2. How should I set to make .retransmit_count effective? And how should I set about the .noack?

  What I want is that when I receive the data it doesn't need to retransmit more times. But if I don't receive data, it should retransmit up to three times until I receive it.When the number of retransmissions reaches three times, it will not retransmit.

Sounds like it's set correctly then. By default it is set to 3, which means you have 3 attempts at retransmitting the payload in case of packet loss.

[Lurn_Z]

Hi,

Through your reply, I can understand like below.

When I set the .selective_auto_ack = false, .noack will not take effect and it should retransmit up to three times until I receive it.

If I set the .selective_auto_ack = true, and .noack = true, it should retransmit up to the MAX retrans times?

If I set the .selective_auto_ack = true, and .noack = false, it will be the same as .selective_auto_ack = false.

Am I right?

Best regards,

Lurn

[Lurn_Z]

Hi Sigurd,

Another question

if (nrf_esb_read_rx_payload(&rx_payload) == NRF_SUCCESS) 

If the above conditions do not hold, what happens next? Will it retransmit automatically, or drop the packet?

Best regards,

Lurn