XB24-BPDK Digi International/Maxstream, XB24-BPDK Datasheet - Page 26

• Manufacturer Part Number: XB24-BPDK
• Description: KIT DEVELOPMENT XBEE SERIES 2
• Manufacturer: Digi International/Maxstream
• Series: XBee™r
• Type: 802.15.4/Zigbeer

Specifications of XB24-BPDK

• Frequency: 2.4GHz
• For Use With/related Products: XBee™ Series 2 Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XBee ZNet 2.5/XBee‐PRO ZNet 2.5 ZigBee OEM RF Modules v1.x4x
R1
Legend
Figure 3‐09. Route Reply Sample Route Reply (Unicast) Where R6 Sends a Route Reply to R3.
Second Route Reply
Note: R6 could send multiple replies if it identifies a better route.
Retries and Acknowledgments
ZigBee includes acknowledgment packets at both the Mac and Application Support (APS) layers.
When data is transmitted to remote device, it may traverse multiple hops to reach the destination.
As data is transmitted from one node to its neighbor, an acknowledgment packet (Ack) is
transmitted in the opposite direction to indicate that the transmission was successfully received. If
the Ack is not received, the transmitting device will retransmit the data, up to 4 times. This Ack is
called the Mac layer acknowledgment.
In addition, the device that originated the transmission expects to receive an acknowledgment
packet (Ack) from the destination device. This Ack will traverse the same path that the data
traversed, but in the opposite direction. If the originator fails to receive this Ack, it will retransmit
the data, up to 2 times until an Ack is received. This Ack is called the ZigBee APS layer
acknowledgment.
Refer to the ZigBee specification for more details.
First Route Reply
© 2008 Digi International, Inc.
R3
R2
C
R4
R5
R6
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