FMR-05D Datasheet, PDF (3/3 Pages) List of Unclassifed Manufacturers – Radio data receiver

FMR-05D DATA FORMAT
It is important to input the correct data format otherwise the receiver will have a lower sensitivity
which will result in a reduced transmission range.
The FMR-05D receiver data slicer is set for 50/50-duty cycle, therefore the “data output” should have
a 50/50-duty cycle. The 50/50-duty cycle data can be pulse-width modulated to transmit resets, 0’s or
1’s. See diagram below :
Logic 1 Logic 0
Average DC Signal
Reset / Start Pulse
Bit 1
Bit 2
A 50/50-duty cycle will have an average DC signal resulting in a constant reference for the data slicer.
Users should use pulse-width modulation to transmit data with logic 1’s or 0’s.
If a different duty cycle is used, for example 66/33 (Manchester format) the data slicer in the receiver
will try to adjust itself to the average DC signal. Since this average DC signal is changing with
different data bits this will result in a constantly changing reference for the data slicer, resulting in
lower sensitivity. See diagram below :
Logic 1
Changing DC Signal
Logic 0
Only 50/50 duty cycle data is suitable for the FMT-2705 transmitter and FMR-05D receiver.
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