OG_MU-4-434_v10e Circuit Design, Inc.
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OPERATION GUIDE
8.5.2
Data synchronization using UART
With the MU-4 set to the transparent mode, the transmission data input at the DI terminal will be wirelessly
transferred as it is, and the data received at DO terminal will be output in positive logic as it is.
The length of continuous 1 or 0 data that can be dealt with the DI and DO terminals is 6 ms or less (28 btis for
4800 bps).
When using UART for wireless transmission, it is important how the start of the data can be detected.
In the figure below, the transmitter transmits 5 ms of High period between the preamble data and the user
data (including the ID code) in the data frame.
The receiver detects the High period and knows the start of the user data.
If the receiver cannot detect the High period in the received data, the data needs to be processed as invalid
data, such as being discarded.
Transmission
Reception
Preamble data
User data
High period 5ms
Preamble data
User data
Transmission
Data to be discarded
Detection of
High period
4ms
Valid data
