Operation of the device
XTR-8LR-4ZN has a unique serial number therefore it always needs to be paired with Aurel XTR-8LR-DEC
(decoder) module by means of learning procedure described in decoder user manual.
The device is always in power down mode and it has 2uA maximum current consumption.
When at least one button is pressed the device transmits, with an encrypted rolling code packet, the buttons
status, the unique serial number, the battery level and an incremental counter.
The RF transmission carries on if at least one button is pressed.
The auto-shutoff function automatically stops the device from transmitting if a button inadvertently gets
pressed for a long period of time. This will prevent the device from draining the battery if a button gets
pressed while the transmitter is in a pocket or purse. Time-out period is approximately 5 seconds.
As described above the keyfob transmits the buttons status, the unique serial number, the battery level and
the incremental counter.
The buttons status field in the RF packet is updated every time there is a change in buttons pressure.
The counter field in the RF packet is increased only before the first RF packet transmission after device wake
up from power down mode.
We suppose, for example, that button 1 is pressed: the device sends RF packets with this button status
information and a with counter of value "n". If, for example, button 2 is pressed too, the keyfob sends RF
packets with information of button 1 and button 2 pressed and a counter with value "n".
See the XTR-8LR-DEC user manual for information about decoder outputs activation in case of more
buttons pressed on keyfob.
When all buttons are released the RF transmission ends and the device goes in reception mode waiting for
ACK packet from decoder. Then the device goes in power down mode.
If the XTR-8LR-DEC has received a valid data packet it sends an acknowledgment packet (ACK) to the
keyfob indicating that the output of the decoder has been activated and his status.
The RGB led on the keyfob blinks during the RF packet transmission:
•if the battery level is ok (V>2.4V) the GREEN led blinks;
•if the battery level is low (V<2.4V) the RED led blinks.
If the keyfob receives the ACK packet from the decoder, the led blinks in a different way depending on the
activated output status:
•if the output is MONOSTABLE the GREEN led will be ON for 600msec;
•if the output is BISTABLE and it has been DEACTIVATED the GREEN led blinks 3 times;
•if the output is BISTABLE and it has been ACTIVATED the RED led blinks 3 times;
If the last packet received from decoder has button status field with two or more buttons pressed, the decoder
sends an ACK packet with a "warning information". In this case on the keyfob the RED led will be on for
600 msec.
During the ACK led blink the buttons pressures aren't handled. It is therefore necessary waiting for the end
of ACK blinks before pressing again a button and restart the RF transmission.
