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AT commands
Default
N/A
MAC/PHY commands
The following AT commands are MAC/PHY commands.
CM (Channel Mask)
This command applies to the XBee SX 868 RF Module.
CM allows you to selectively enable or disable channels used for RF communication. This is useful to
avoid using frequencies that experience unacceptable levels of RF interference, or to operate two
networks of radios on separate frequencies.
This mask limits the channels where the device transmits. See
frequencies. Channel 0 is bit 0. You must enable at least two channels, except when using only a single
frequency of 869.85 MHz. When you use this mode (use 0x20000000), LBT+AFA is disabled and the
power level is automatically limited to 5 dBm.
This command is a bitfield.
Exactly
MF (Minimum Frequency Count)
communicate on.
The CM command does not limit receive channels. If two devices have mutually exclusive values for
CM (for example 0x0000FF00 and 0x000000FF), then communication is possible because both devices
still listen on all possible channels, while limiting the transmission channels to those specified in the
CM command.
The CM channel mask no longer supports channels 9 and 24 due to regulatory requirements.
Parameter range
3 - 0x3EFFFDFF [bitfield]
Default
Europe: 0x3EFFFDFF (channels 0 - 29, 863.15 - 869.85 MHz), excluding channels 9 and 24
Europe (single frequency mode): 0x20000000 (channel 29, 869.85 MHz)
HP (Preamble ID)
This command applies to the XBee SX 868 RF Module.
The preamble ID for which the device communicates. Only devices with matching preamble IDs can
communicate with each other. Different preamble IDs minimize interference between multiple sets of
devices operating in the same vicinity. When receiving a packet, the device checks this before the
network ID, as it is encoded in the preamble, and the network ID is encoded in the MAC header.
Parameter range
0 - 9
Default
0
XBee® SX 868 RF Module User Guide
Technical specifications
number of channels must be made available for the device to
MAC/PHY commands
for the list of
114
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