User's Manual

XBee®/XBee‐PRO®ZBRFModules
©2009DigiInternational,Inc. 34
These behaviors are configurable using the following commands:
Permit Joining
The permit joining attribute on the router is configurable with the NJ command. NJ can be
configured to always allow joining, or to allow joining for a short time.
Joining Always Enabled
If NJ=0xFF (default), joining is permanently enabled. This mode should be used carefully. Once a
network has been deployed, the application should strongly consider disabling joining to prevent
unwanted joins from occurring.
Joining Temporarily Enabled
If NJ < 0xFF, joining will be enabled only for a number of seconds, based on the NJ parameter. The
timer is started once the XBee joins a network. Joining will not be re-enabled if the module is
power cycled or reset. The following mechanisms can restart the permit-joining timer:
• Changing NJ to a different value (and applying changes with the AC or CN commands)
• Pressing the commissioning button twice (enables joining for 1 minute)
• Issuing the CB command with a parameter of 2 (software emulation of a 2 button press -
enables joining for 1 minute)
• Causing the router to leave and rejoin the network.
Router Network Connectivity
Once a router joins a ZigBee network, it remains connected to the network on the same channel
and PAN ID as long as it is not forced to leave. (See Leaving a Network section for details.) If the
scan channels (SC), PAN ID (ID) and security settings (EE, KY) do not change after a power cycle,
the router will remain connected to the network after a power cycle.
If a router may physically move out of range of the network it initially joined, the application
should include provisions to detect if the router can still communicate with the original network. If
communication with the original network is lost, the application may choose to force the router to
leave the network (see Leaving a Network section for details). The XBee firmware includes two
provisions to automatically detect the presence of a network, and leave if the check fails.
Power-On Join Verification
The JV command (join verification) enables the power-on join verification check. If enabled, the
XBee will attempt to discover the 64-bit address of the coordinator when it first joins a network.
Once it has joined, it will also attempt to discover the 64-bit address of the coordinator after a
power cycle event. If 3 discovery attempts fail, the router will leave the network and try to join a
new network. Power-on join verification is disabled by default (JV defaults to 0).
Command Description
NJ Sets the permit-join time on
the router, or the time that it
will allow new devices to join
the network, measured in
seconds. If NJ=0xFF, permit
joining will always be enabled.
D5 Enables the Associate LED
functionality.
LT Sets the Associate LED blink
time when joined. Default is 2
blinks per second (router).