Lopy4 nano gateway changes downlinks SF and frequency with SF12

  • hi, i am using lopy4 as gateway and with SF7BW125 works ok, but when I try to use it with SF12BW125 I can’t receive downlinks, I have checked in the terminal the messages of the gateway and with SF7 it sends a downlink at 868.1Mhz and SF7BW125, but when I change to SF12 it sends a downlink at 869.525Mhz and SF9BW125 so I don’t know if I need to modify something in the gateway in order that it sends the downlink in 868.1Mhz and SF12BW125 when is configured with SF12 or I must modify the node?, thanks

  • @mfalkvidd I also have changed my node config to:

    #define EU868_RX_WND_2_FREQ                         869525000
    #define EU868_RX_WND_2_DR                           DR_3

    but the downlink is not received, lopy4 is configured with SF12BW125 and DR0, I can see the downlink from the gateway and the frequency and SF match with my node config but it doesn't work, uplinks are OK

    [   786.969] Sent downlink packet scheduled on 246.579, at 869.525 Mhz using SF9BW125: b'`\xf7\x1f\x01&\x00\x01\x00\x01@\xceK\x9c\xe2'

  • @mfalkvidd ok thanks, I have read that info but what does it mean?, I am confused because the default config of my node is this:

     * Second reception window channel frequency definition.
    #define EU868_RX_WND_2_FREQ                         869525000
     * Second reception window channel datarate definition.
    #define EU868_RX_WND_2_DR                           DR_0

    BUT... as I mentioned before, when I am using SF7BW125 uplinks and downlinks works, and I don't know why because the gateway sends the downlink with SF7BW125 and the node RX2 has DR0 (SF12), so it shouldn't work

  • @jg_spitfire are you using TTN? If so, https://www.thethingsnetwork.org/docs/lorawan/frequency-plans.html says

    Note that The Things Network uses the non-standard SF9BW125 data rate for RX2 in Europe. If your devices use OTAA, this will be configured automatically when they join. If your devices use ABP, you’ll need to program this RX2 data rate into the devices in order to make them work with TTN.

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