Programming instructions

Atmel AT02597: ZigBee PRO Packet Analysis with Sniffer [APPLICATION NOTE]
32210A−WIRELESS−09/2013
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When a node starts up, it does network discovery by performing an active scan over the channels specified in the
CS_CHANNEL_MASK parameter in BitCloud. A beacon request is sent as seen in packet #4 in Figure 4-2.
Upon receptio
n of a beacon request frame, routers and coordinators already present in network automatically respond
with a beacon frame. The joining node filters a potential parent based on the settings in the beacon packet received.
Figure 4-2. Node Joins Network Via MAC Association Using IEEE Address 0x55ULL.
The beacon from the coordinator/router contains the Association Permit subfield, it is set to TRUE if the device is
accepting association to the PAN. A joining node cannot associate to the device if this sub-field is FALSE.
CS_PERMIT_DURATION controls the joining of devices into the network by setting the permit duration.
Figure 4-3. assocPermit Sub-Field in the Beacon Frame.
Example:
Figure 4-4 shows parsed beacon payload that contains information based on which the joining node
chooses a potential parent.
The beacon payload provides information on the ZigBee stack profile used in the network (ZigBee PRO = 0x02),
network protocol version (nwkcProtocolVersion, 0x02 as per ZigBee PRO specification). The router capacity, end-
device capacity and device depth limits the acceptance of children by a parent node.