Operation
Addressing
Addressing
Every RF data packet sent over-the-air contains a Source Address and Destination Address field in its
header. The XBee/XBee-PRO S2C 802.15.4 RF Module conforms to the 802.15.4 specification and
supports both short 16-bit addresses and long 64-bit addresses. A unique 64-bit IEEE source address is
assigned at the factory and can be read with the SL (Serial Number Low) and SH (Serial Number High)
commands. You must manually configure short addressing. A device uses its unique 64-bit address as
its Source Address if its MY (16-bit Source Address) value is 0xFFFF or 0xFFFE.
Send packets to a specific device
To send a packet to a specific device using 64-bit addressing:
n
Set the Destination Address (DL + DH) of the sender to match the Source Address (SL + SH) of
the intended destination device.
To send a packet to a specific device using 16-bit addressing:
1. Set the DL parameter to equal the MY parameter of the intended destination device.
2. Set the DH parameter to 0.
Addressing modes
802.15.4 frames have a source address, a destination address, and a destination PAN ID in the over-
the-air (OTA) frame. The source and destination addresses may be either long or short and the
destination address may be either a unicast or a broadcast. The destination PAN ID is short and it may
also be the broadcast PAN ID.
In Transparent mode, the destination address is set by the DH and DL parameters, but, in API mode, it
is set by the TX Request: 64-bit address (0x00) or TX Request: 16-bit Address (0x01) frames. In either
Transparent mode or API mode, the destination PAN ID is set with the ID parameter, and the source
address is set with the MY parameter.
Broadcasts and unicasts
Broadcasts are identified by the 16-bit short address of 0xFFFF. Any other destination address is
considered a unicast and is a candidate for acknowledgments, if enabled.
Broadcast PAN ID
The Broadcast PAN ID is also 0xFFFF. Its effect is to traverse all PANs in the vicinity. Typically, this only
makes sense during association time when sending beacon requests to find PAN IDs.
Short and long addresses
A short address is 16 bits and a long address is 64 bits. The short address is set with the MY
parameter. If the short address is 0xFFFE or 0xFFFF, then the address of the device is long and it is the
serial number of the device as read by the SH and SL parameters.
Note When an end device associates to a coordinator, it is assigned the short address of 0xFFFE.
Encryption
The XBee/XBee-PRO S2C 802.15.4 RF Module supports AES 128-bit encryption. 128-bit encryption
refers to the length of the encryption key entered with the KY command (128 bits = 16 bytes). The
XBee/XBee-PRO S2C 802.15.4 RF Module User Guide
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ETC [ ETC ]
