Used in ABP, set or read NwkSKey, return Y1Y2 ... Y16, hexadecimal format, value
16 bytes.
<mask>: The frequency point mask that the network may work, 16bit
corresponds to 16 frequency groups, see the LoRaWAN access
specification for details.
Such as: 0-7 channels, the corresponding mask is 0001, the
corresponding mask of 8-15 channels is 0002, the corresponding mask
of 16-23 channels is 0004 and so on .
the frequency corresponding to the specific channel, you need to check
the region protocol. For example, channels 0-7 correspond to:
470.3MHz, 470.5MHz, 470.7MHz, 470.9MHz, 471.1MHz, 471.3MHz,
471.5MHz, 471.7MHz in CN470 .