XBP24-BPIT-004 Digi International, XBP24-BPIT-004 Datasheet - Page 24

• Manufacturer Part Number: XBP24-BPIT-004
• Description: Zigbee / 802.15.4 Modules XBee-PRO Znet 2.5 PCB Antenna
• Manufacturer: Digi International

Specifications of XBP24-BPIT-004

• Rohs: yes
• Frequency Band: 2.4 GHz
• Line Of Sight Range: 100 m
• Data Rate: 250 Kbps
• Sensitivity: - 102 dBm
• Operating Supply Voltage: 3 V to 3.4 V
• Output Power: 63 mW
• Antenna Connector Type: PCB
• Maximum Operating Temperature: + 85 C

XBee ZNet 2.5/XBee‐PRO ZNet 2.5 ZigBee OEM RF Modules v1.x4x
not endlessly transmitted. Each entry persists for 8 seconds. The broadcast transmission table
holds 8 entries.
For each broadcast transmission, the ZigBee stack must reserve buffer space for a copy of the
data packet. This copy is used to retransmit the packet as needed.Large broadcast packets will
require more buffer space.
Since broadcast transmissions are retransmitted by each device in the network, broadcast
messages should be used sparingly.
Unicast Transmissions
Unicast ZigBee transmissions are always addressed to the 16-bit address of the destination
device. However, only the 64-bit address of a device is permanent; the 16-bit address can change.
Therefore, ZigBee devices may employ network address discovery to identify the current 16-bit
address that corresponds to a known 64-bit address, and route discovery to establish a route.
Network Address Discovery
Data transmissions are always sent to the 16-bit network address of the destination device.
However, since the 64-bit address is unique to each device and is generally known, ZigBee devices
must discover the network address that was assigned to a particular device when it joined the PAN
before they can transmit data.
To do this, the device initiating a transmission sends a broadcast network address discovery
transmission throughout the network. This packet contains the 64-bit address of the device the
initiator needs to send data to. Devices that receive this broadcast transmission check to see if
their 64-bit address matches the 64-bit address contained in the broadcast transmission. If the
addresses match, the device sends a response packet back to the initiator, providing the network
address of the device with the matching 64-bit address. When this response is received, the
initiator can then transmit data.
Route Discovery
ZigBee employs mesh routing to establish a route between the source device and the destination.
Mesh routing allows data packets to traverse multiple nodes (hops) in a network to route data
from a source to a destination. Routers and coordinators can participate in establishing routes
between source and destination devices using a process called route discovery. The Route
discovery process is based on the AODV (Ad-hoc On-demand Distance Vector routing) protocol.
Figure 3‐07. Sample Transmission Through a Mesh Network
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© 2008 Digi International, Inc.
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