UG124 Datasheet, PDF (8/18 Pages) Silicon Laboratories – ZigBee Contact Sensor Reference Design Kit

5. Operation
UG124: ZigBee^® Contact Sensor Reference Design (RD-0030-0201) Kit User's Guide
Operation
5.1 ZigBee Network Behavior
This section describes the various operational states a powered contact sensor reference design is able to occupy as it joins and leaves
a ZigBee network. The input mechanism for operation utilizes a join button, S1. The red LED operates as output signaling information
as the reference design traverses or occupies a functional state. Refer to the figure below for a pictorial representation of this process.
TAMPER DETECTED
Alarm message sent
OFF NETWORK
No LED Flashes
If button held
>4 seconds
is released
IDENTIFY
Two LED flashes per
two seconds for three minutes
Mode time out
Two button presses
ON NETWORK
No LED flashes
Three button presses
Mode time out
NETWORK STATUS
Six LED flashes
No joinable network
found for three minutes
Button press,
or power cycle
ACTIVE NTWK SEARCH
Button held >4
seconds activates
tamper monitoring
One LED flash per
two seconds
Joinable network
found
NETWORK JOIN
Six LED flashes
A button press resets
three minute timer
Blink cycle ends
LEAVE NETWORK
Three LED flashes per
two seconds
No response from network
-or-
Network _found
4 button presses
-or-
power cycle
One button
press >1 second
No response from
network, wait
15 minutes
One button
press >1 second
REJOIN NETWORK
No LED flashes
Figure 5.1. Device Operation State Diagram
5.1.1 First Time Contact Sensor Power-up
After the hardware has been powered for the first time, the device will be in a factory default mode and will be placed in the ACTIVE
NTWK SEARCH state. If the dimmer switch successfully joins a network is powered off at a later time, upon re-powering, it will enter
the REJOIN NETWORK state instead of the ACTIVE NTWK SEARCH state.
5.1.2 OFF NETWORK State
This state is a condition where the design is not connected to a network and is not searching for a network. To leave this state and
enter the ACTIVE NTWK SEARCH state, press the S1 button one time.
5.1.3 ACTIVE NTWK SEARCH State
This state is a condition where the contact sensor is actively searching for a network but has not yet joined a network. While in this
mode, the D1 LED will flash once every two seconds. This operation of actively searching for a network will remain for up to three mi-
nutes. If no network is found by the three minute time limit, the contact sensor will enter into the OFF NETWORK state. Power-cycling
or a button press while in this state will reset the three minute timer, while keeping the contact sensor in this state. If a network is found
it will leave this state and enter the NETWORK JOIN state.
5.1.4 NETWORK JOIN State
After a contact sensor leaves the ACTIVE NTWK SEARCH state and enters this state, the D1 LED will flash six times to indicate suc-
cessfully finding and joining a network. This state is temporary and will place the contact sensor into the ON NETWORK state once the
LEDs complete their flash sequence. Power cycling will only impair the LED flashes, and will not prevent entry into the ON NETWORK
STATE once the power is reapplied.
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