Specifications
XBee®/XBee‐PRO®SERFModules
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Parent Connectivity
The XBee Smart Energy end device sends regular poll transmissions to its parent when it is awake.
These poll transmissions query the parent for any new received data packets. The parent always
sends a MAC layer acknowledgment back to the end device. The acknowledgment indicates
whether the parent has data for the end device or not.
If the end device does not receive an acknowledgment for 3 consecutive poll requests, it considers
itself disconnected from its parent and will attempt to discover and join a valid ZigBee network.
See "Managing End Devices" chapter for details.
Resetting the End Device
When the end device is reset or power cycled, if the orphan scan successfully locates a parent, the
end device then checks its PAN ID, operating channel against the network configuration settings
(ID, SC). If the end device's PAN ID or operating channel is invalid, the end device will leave the
network and attempt to join a new network based on its network joining command values.
To prevent the end device from leaving an existing network, the WR command should be issued
after all network joining commands have been configured in order to retain these settings through
power cycle or reset events.
Leaving a Network
There are a couple of mechanisms that will cause the end device to leave its current PAN and
attempt to discover and join a new network based on its network joining parameter values. These
include the following:
• The ID command changes such that the current 64-bit PAN ID is invalid.
• The SC command changes such that the current operating channel (CH) is not included in the
channel mask.
• The NR0 command is issued to cause the end device to leave.
• The commissioning button is pressed 4 times or the CB command is issued with a parameter
of 4.
• The end device's parent is powered down or the end device is moved out of range of the par-
ent such that the end device fails to receive poll acknowledgment messages.
Note that changes to command values only take effect when changes are applied (AC or CN
commands).
Example: Joining a Network
After starting a coordinator (that is allowing joins), the following steps will cause an XBee end
device to join the network:
1. Set ID to the desired 64-bit PAN ID, or to 0 to join any PAN.
2. Set SC to the list of channels to scan to find a valid network.
3. If SC or ID is changed from the default, apply changes (make SC and ID changes take effect)
by issuing the AC or CN command.
4. The Associate LED will start blinking once the end device has joined a PAN.
Command Description
LT
Sets the Associate LED blink time when joined. Default is 2 blinks per
second (end devices).
SM, SP, ST, SN,
SO
Parameters that configure the sleep mode characteristics. (See
Managing End Devices chapter for details.)