Node parameters

When configuring a node, it is necessary to set some parameters which will be used lately in the network, and some parameters necessary for using the API functions.

MAC address

A 64-bit RF module's unique IEEE address. It is divided in two groups of 32 bits (High and Low).

It identifies uniquely a node inside a network due to it can not be modified and it is given by the manufacturer.

Example of use:

{
    xbee900HP.getOwnMacLow(); // Get 32 lower bits of MAC Address
    xbee900HP.getOwnMacHigh(); // Get 32 upper bits of MAC Address
}

Related variables:

xbee900HP.sourceMacHigh[0-3] → stores the 32 upper bits of MAC address

xbee900HP.sourceMacLow [0-3] → stores the 32 lower bits of MAC address

Besides, XBee modules provide a stick on the bottom side where the MAC address is indicated:

PAN ID

The Personal Area Network Identifier (PAN ID) is the Network ID. The user network identifier. Nodes must have the same network identifier to communicate. Only modules with matching IDs can communicate with each other so all the nodes in the same network must have the same PAN ID. If using OEM network IDs, 0xFFFF will use the factory value.

Parameter range: From 0 to 0x7FFF

Default: 0x7FFF

Example of use:

{
    uint8_t panid[] = { 0x7F, 0xFF };
    xbee900HP.setPAN(panid);
    xbee900HP.getPAN();
}

Related variables:

xbee900HP.PAN_ID[0-7] → stores the 16-bit PAN ID. It is stored in the two first positions.

XBee configuration example:

https://development.libelium.com/waspmote/900hp-01-configure-xbee-parameters

Node identifier

It is an ASCII string of 20 characters at most which identifies the node in a network. It is used to identify a node in the application level. It is also used to search a node using its NI.

Example of use:

{
    xbee900HP.setNodeIdentifier("node01");
    xbee900HP.getNodeIdentifier();
}

Related variables:

xbee900HP.nodeID[0-19] → stores the 20-byte max string Node Identifier

Available frequencies

XBee 900HP defines 64 channels that are spaced 400 kHz apart:

  • 902-928MHz : 64 channels

This read-only command can be queried to return a bitfield of the frequencies that are available in the module's region of operation. Each bit corresponds to a physical channel. Channels are spaced 400 kHz apart:

Bitfield

Frequency (MHz)

Bitfield

Frequency (MHz)

Bit 0

902.400

Bit 32

915.200

Bit 1

902.800

Bit 33

915.600

Bit 2

903.200

Bit 34

916.000

Bit 3

903.600

Bit 35

916.400

Bit 4

904.000

Bit 36

916.800

Bit 5

904.400

Bit 37

917.200

Bit 6

904.800

Bit 38

917.600

Bit 7

905.200

Bit 39

918.000

Bit 8

905.600

Bit 40

918.400

Bit 9

906.000

Bit 41

918.800

Bit 10

906.400

Bit 42

919.200

Bit 11

906.800

Bit 43

919.600

Bit 12

907.200

Bit 44

920.000

Bit 13

907.600

Bit 45

920.400

Bit 14

908.000

Bit 46

920.800

Bit 15

908.400

Bit 47

921.200

Bit 16

908.800

Bit 48

921.600

Bit 17

909.200

Bit 49

922.000

Bit 18

909.600

Bit 50

922.400

Bit 19

910.000

Bit 51

922.800

Bit 20

910.400

Bit 52

923.200

Bit 21

910.800

Bit 53

923.600

Bit 22

911.200

Bit 54

924.000

Bit 23

911.600

Bit 55

924.400

Bit 24

912.000

Bit 56

924.800

Bit 25

912.400

Bit 57

925.200

Bit 26

912.800

Bit 58

925.600

Bit 27

913.200

Bit 59

926.000

Bit 28

913.600

Bit 60

926.400

Bit 29

914.000

Bit 61

926.800

Bit 30

914.400

Bit 62

927.200

Bit 31

914.800

Bit 63

927.600

Figure: Available frequencies on XBee 900HP

Parameter range: From 0x1FFFFFF to 0x00FFFFFFFFFFFFFFFF

Default:

  • USA/Canada version → 0x00FFFFFFFFFFFFFFFF (channels 0 -- 63)

  • Australia version → 0x00FFFFFFFE00000000 (channels 33 -- 63)

  • Brazil version → 0x00FFFFFFFE00000FFF (channels 0 -- 11, 33 -- 63)

Example of use:

{
    xbee900HP.getAvailableFreq();
}

Related variables:

xbee900HP._availableFreq[0-7] → stores the available frequencies bitfield

Channel mask

The channel mask command allows channels to be selectively enabled or disabled. This is useful to avoid using frequencies that experience unacceptable levels of RF interference. This command is a bitfield. Each bit in the bitfield corresponds to a frequency as defined in the "Available Frequencies" section. When a bit in the Channel Mask and the corresponding bit in the Available Frequencies are both set to 1 then that physical channel may be chosen by the module as an active channel for communication.

The minimum number of channels required for operation can be queried with the Minimum Frequencies (MF) command. If a Channel Mask setting would result in less than MF active channels being enabled, then an error will be returned. If there are more active channels enabled than required by MF, then the first MF frequencies will be used (higher active frequencies may be unused in favor of lower ones).

All modules in a network must use an identical set of active channels. Separate networks which are in physical range of each other should use different Preamble Patterns (HP) and/or Network ID's (ID) to avoid receiving data from the other network.

Parameter range: From 0x1FFFFFF to 0x00FFFFFFFFFFFFFFFF

Default: 0xFFFFFFFFFFF7FFFF

Channel 19 (910.000 MHz) is disabled by default. This channel has approximately 2 dBm worse receiver sensitivity than other channels. It is suggested not to use this channel.

The user must keep in mind that depending on the region, the XBee module supports different frequency channels. Although it is possible to enable all channels in the channel mask, the XBee module will be forced to use the available channels for the corresponding region. More precisely, the available frequencies for each region are:

Region

Bitfield

Channels

USA/Canada

0x00FFFFFFFFFFFFFFFF

0 – 63

Australia

0x00FFFFFFFE00000000

33 – 63

Brazil

0x00FFFFFFFE00000FFF

0 – 11, 33 – 63

Example of use:

{
    uint8_t channelMask[8] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
    xbee900HP.setChannelMask( channelMask );
    xbee900HP.getChannelMask();
}

Related variables:

xbee900HP._channelMask[0-7] → stores the channel mask

XBee configuration example:

https://development.libelium.com/waspmote/900hp-01-configure-xbee-parameters

Minimum frequency count

This read-only command can be queried to determine the minimum number of channels that must be enabled with the Channel Mask command for proper operation in the module\'s region of operation.

Parameter range:

From 1 to 50

Default:

USA/Canada → 25

Australia → 25

Brazil → 25

Example of use:

{
    xbee900HP.getMinFreqCount();
}

Related variables:

xbee900HP._minFreqCount → stores the minimum frequency count value

XBee configuration example:

https://development.libelium.com/waspmote/900hp-01-configure-xbee-parameters

Preamble ID

Only modules with matching preamble IDs can communicate with each other. Different preamble IDs minimize interference between multiple sets of modules operating in the same vicinity. When receiving a packet this is checked before the network ID, as it is encoded in the preamble, and the network ID is encoded in the MAC header.

Parameter range: From 0x00 to 0x07

Default: 0x00

Example of use:

{
    xbee900HP.setPreambleID( 0x00 );
    xbee900HP.getPreambleID();
}

Related variables:

xbee900HP._preambleID → stores the preamble ID

XBee configuration example:

https://development.libelium.com/waspmote/900hp-01-configure-xbee-parameters

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