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,

Fabian

@fminary1

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.

image

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,

Fabian

@fminary1

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.

Hello Martin
I would also like to do some tests with AFSK.
I have the testboard DVK-2c and the software AX-RadioLAB v2.11a but i can’t select AFSK in the selection menu. Do I need another AX-RadioLAB version?
best regards
MJ

@mj1

This is available by entering “1962” into the TX periodic field in the main window and click enter.
At that point, AFSK shaped modulation (and others) are available from the PHY window of RadioLab.

image

Thank you for using our community forum!

It works. Thank you. :wink:

Hello Martin
I have now made various tests. The 1200 Bps with Mark/Space 1200/2200 Hz work very well. Also 600 Bps with Mark/Space 600/1200Hz work very well. However, I would now have an application working with 2400Bps with Mark/Space 1200/2400 Hz and that works very poorly. Only every 4 or 5 data transfers work. I still tried 4800 Bps with Mark/Space 2400/4800Hz. This works as bad as the 2400 Bps.
Do data rates greater than 1200 Bps not go with the AFSK modulation in principle, because this was not developed for it or do I do something wrong?
best regards
MJ

Good day.
I have now made a few more experiments with different Mark and Space frequencies. 2400 Bps on air work with different frequencies. Mark=2400 Hz and Space=4800 Hz works. Mark=600 Hz and Space=2400 Hz also works.
But Mark=1200 Hz and Space=2400 Hz does not work.
But if I change the mark frequency to 1000 Hz or the space frequency to 2800 Hz it works again.
There is a bug in there somewhere.
best regards
MJ