User Manual

RIGOL 7 Protocol Decoding
DS4000 User’s Guide
7-6
Stop Bit
Check Bit
Start Bit
Data Bits
Start Bit: represent when the data starts outputting. Setting the Polarity is
equivalent to specifying the “Start Bit”.
Data Bits: represent the number of data bits actually contained in each frame of
data.
Even-OddCheck: be used to check the correctness of the data transmission.
 Odd-Check: the number of “1” in the data bit and check bit is an odd. For
example, when 0x55 (01010101) is sent, a 1 needs to be filled in the check bit to
make the number of 1 to be an odd.
 Even Check: the number of “1” in data bit and check bit is an even. For example,
when 0x55 (01010101) is sent, a 0 should be filled in the check bit.
 None: there would not be check bit during the transmission.
Press Decode1  Decode to select “RS232” to open the RS232 decoding function
menu.
1. TX and RX Channel Setting
Press TX to select any channel (CH1 to CH4) as the transmitting channel and
when “OFF” is selected, no transmitting channel is set. Use the same method
the set the RX channel. What’s more, you need to set the thresholds of the input
channels of TX and RX. Switch the menu page and press TXThreshold and
RXThreshold respectively to input the desired threshold values.
2. Polarity Setting
Press Polarity to select “-” (negative polarity) or “+” (positive polarity) and the
default is negative polarity. The oscilloscope will select the rising or falling edge
as the start position during decoding.
3. Endian Setting
Press Endian to select “LSB” or “MSB” and the default is “LSB”.
4. Baud Rate Setting
Press Baud to select the desired baud rate and the default is 9600bps.