problem about AT%XCBAND=?

hi support team,

customer had one problem about "AT%XCBAND=? "

first. Customer try to set catm and catnb systemmode together as below, i could not see the band17 in list:

[16:43:53.099] AT%XFACTORYRESET=0

[16:48:21.233]

[16:48:21.233] OK

[16:48:21.233] AT%XFACTORYRESET=1

[16:48:23.659]

[16:48:23.659] OK

[16:48:23.659] AT%XBANDLOCK=1,"10001100000001010"

[16:48:26.335]

[16:48:26.335] OK

[16:48:26.335] AT%XBANDLOCK=2,"10001100000001010"

[16:48:29.173]

[16:48:29.173] OK

[16:48:29.173] AT%XCBAND=?

[16:48:32.368]

[16:48:32.368] %XCBAND: (2,4,12,13)

then we change systemmode to catnb only, it shows band17 as below:


[16:49:16.633] AT%XSYSTEMMODE=0,1,0,0
[16:49:21.557]
[16:49:21.557] OK
[16:49:21.557] AT%XCBAND=?
[16:49:26.089]
[16:49:26.089] %XCBAND: (2,4,12,13,17)

then. i start the modem as AT+CFUN=1, the band 17 show quite slow:

[16:49:56.018] AT+CFUN=1

[16:50:02.586]

[16:50:02.586] OK

[16:50:02.586] AT%XCBAND=?

[16:50:08.516]

[16:50:08.516] %XCBAND: (2,4,12,13)

[16:50:08.516]

[16:50:08.516] OK

[16:50:08.516] AT%XCBAND=?

[16:50:13.511]

[16:50:13.511] %XCBAND: (2,4,12,13)

[16:50:13.511]

[16:50:13.512] OK

[16:50:13.512] AT%XCBAND=?

[16:50:18.510]

[16:50:18.510] %XCBAND: (2,4,12,13)

[16:50:18.512]

[16:50:18.512] OK

[16:50:18.512] AT%XCBAND=?

[16:50:23.519]

[16:50:23.519] %XCBAND: (2,4,12,13,17)

[16:50:23.519]

[16:50:23.519] OK

the question is ,is there any reason for this command? 

Regards,

William.

Parents Reply Children
  • yes,Hakon

    i understand your meaning, my point is band 17 is not listed at the first moment, but shows at about 10 seconds later.

    we have any reason for this?

    [16:50:13.512] AT%XCBAND=?

    [16:50:18.510]

    [16:50:18.510] %XCBAND: (2,4,12,13)

    [16:50:18.512]

    [16:50:18.512] OK

    [16:50:18.512] AT%XCBAND=?

    [16:50:23.519]

    [16:50:23.519] %XCBAND: (2,4,12,13,17)

    Regards,

    William.

  • Hi William,

     

    My apologies for misunderstanding the scenario.

    I tried to recreate this locally, but was not able to do so:

    [2024-11-15 13:59:38] *** Using Zephyr OS v3.7.99-adcffa835a8e ***
    [2024-11-15 13:59:38] The AT host sample started
    [2024-11-15 13:59:38] Ready
    [2024-11-15 13:59:43] AT%XFACTORYRESET=1
    [2024-11-15 13:59:44] OK
    [2024-11-15 13:59:50] AT%XBANDLOCK=1,"10001100000001010"
    [2024-11-15 13:59:50] OK
    [2024-11-15 13:59:54] AT%XBANDLOCK=2,"10001100000001010"
    [2024-11-15 13:59:54] OK
    [2024-11-15 13:59:58] AT%XCBAND=?
    [2024-11-15 13:59:59] %XCBAND: (2,4,12,13)
    [2024-11-15 13:59:59] OK
    [2024-11-15 14:00:04] AT%XSYSTEMMODE=0,1,0,0
    [2024-11-15 14:00:09] OK
    [2024-11-15 14:00:10] AT%XCBAND=?
    [2024-11-15 14:00:10] %XCBAND: (2,4,12,13,17)
    [2024-11-15 14:00:10] OK
    [2024-11-15 14:00:19] at+cfun=1
    [2024-11-15 14:00:21] OK
    [2024-11-15 14:00:21] AT%XCBAND=?
    [2024-11-15 14:00:21] %XCBAND: (2,4,12,13,17)
    [2024-11-15 14:00:21] OK
    [2024-11-15 14:00:22] AT%XCBAND=?
    [2024-11-15 14:00:22] %XCBAND: (2,4,12,13,17)
    [2024-11-15 14:00:22] OK
    [2024-11-15 14:00:23] AT%XCBAND=?
    [2024-11-15 14:00:23] %XCBAND: (2,4,12,13,17)
    [2024-11-15 14:00:23] OK
    [2024-11-15 14:00:23] AT%XCBAND=?
    [2024-11-15 14:00:23] %XCBAND: (2,4,12,13,17)
    [2024-11-15 14:00:23] OK

    Which modem fw are you running? This can be read out using "at+cgmr"

    I was running this on mfw v1.3.6.

     

    Kind regards,

    Håkon

  • yes Hakon,

    the same mfm1.3.6 as you.

    You are reproducing my question, you can set AT%XSYSTEMMODE=1,1,0,0, and please try again.

    you can see that %XCBAND: (2,4,12,13,17) appears at about 15 seconds.

    Regards,

    William.

  • Hi William,

     

    If we look at the documentation for XSYSTEMMODE:

    https://docs.nordicsemi.com/bundle/ref_at_commands/page/REF/at_commands/mob_termination_ctrl_status/xsystemmode_set.html

    You are enabling both NB + LTE-M modes, then enabling the modem. It will start up with LTE-M and then switch over to NB-IoT. Could this be the reason why you're seeing this behavior?

     

    Try setting "at+cereg=5" and checking the return (at+cereg?) for each time you poll the %XCBAND to verify which mode is used.

     

    Kind regards,

    Håkon

Related