AX5043 13% Frame lost in AFSK 1200 bit/s

Hello everyone,

We have a product which communicates in afsk and gmsk.

In gmsk all is ok and working well but in afsk 1200 we have around 12% of frame lost !

Have someone encountered a problem like this and where can be possible comming from. (Tested with SDR and also an afsk modem same result).

Thank you for your response.

Best regards,



We can recommend our community forum thread for detailed AFSK1200 settings.

AFSK1200 reception - #4 by korneliuszo

I have set our 2x DVK-2 kits for AFSK modulation @ 1.2 kBits/s to test communication between TX and RX,

I have on the SLAVE side checked Send ACK for lost packets and they were zero in this test.


This is how it looks like on debugger link as well:

Thank you for using our community forum!

My problem is with enabling HDLC

I’m sure that in your test you are getting 0% error rate but in my case I wonder why I have not this result.

If my afsk programmation paramters were wrong I would not be able to receive any packet and if my code were wrong It would be not working either in gmsk.

So I wonder where that could be coming from and it is critical for our application. Would you suggest me to reconsider the ax5043 programmation parameters ?

Best regards,



Can we please answer the following :

  • How are you assessing the packet loss, with what tool and over how long ?

  • what is the RSSI level on this testbed ?

  • what freq is being used?

    Have you tried to replicate using the AX Radio Config Utility default settings ?
    If yes, can you please provide a tar ball of the project directory for us to run a diff and validate ?

If you can choose GFSK or AFSK, then choose GFSK.

AFSK used in old legacy application, it has disadvantage over noise environment.

When the number of adjacent stations with strong signals, you risk “losing” the tuning.

For reliable radio, should choose GFSK.