RIGOL MSO/DS2000A Series - Manual (Page 184)

RIGOL Chapter 8 Protocol Decoding
8-6 MSO2000A/DS2000A User’s Guide
Start Bit: represent when the data starts outputting.
Data Bits: represent the number of data bits actually contained in each frame of
data.
Check Bit: used to check the correctness of the data transmission.
 Odd Checkout: the total 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 be an odd.
 Even Checkout: the total number of “1” in the 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.
 Stop Bit: represent when the data stops outputting.
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, CH2 or any channel of D0-D15) as the
transmitting channel and when “None” is selected, no transmitting channel is set.
Use the same method the set the RX channel.
When an analog channel is selected for TX or RX, you need to set a threshold
by pressing the TX or RX menu. The range is from (-5 * vertical scale - vertical
position) to (5 * vertical scale - vertical position) and the default is 0V.
2. Polarity Setting
Press Polarity to select “Normal” (negative logic, namely the high level is logic
“0” and the low level is logic “1”) or “Invert” (positive logic, namely the high level
is logic “1” and the low level is logic “0”) and the default is “Normal”.
3. Copy Trigger
Press CopyTrig to config the decoder parameter from the corresponding trigger.
In RS232 decoding, the function can only be enabled when the trigger type is
RS232 trigger, and you can copy the parameter of data channel, data bits, baud,
stop bit, Even-Odd and polarity.
4. Endian Setting
Press Endian to select “LSB” or “MSB” and the default is “LSB”.