Keysight DSOX3012T, User Manual

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512 Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide
33
UART/RS232 Triggering and Serial Decode
5 For both the Rx and Tx signals:
a Connect an oscilloscope channel to the signal in the device under test.
b Press the Rx or Tx softkey; then, turn the Entry knob to select the channel for
the signal.
c Press the corresponding Threshold softkey; then, turn the Entry knob to select
the signal threshold voltage level.
The threshold voltage level is used in decoding, and it will become the
trigger level when the trigger type is set to the selected serial decode slot.
The RX and TX labels for the source channels are automatically set.
6 Press the Back/Up key to return to the Serial Decode Menu.
7 Press the Bus Config softkey to open the UART/RS232 Bus Configuration Menu.
Set the following parameters.
a #Bits — Set the number of bits in the UART/RS232 words to match your
device under test (selectable from 5-9 bits).
b Parity — Choose odd, even, or none, based on your device under test.
c Baud — Press the Baud Rate softkey, then press the Baud softkey and select a
baud rate to match the signal in your device under test. You can select baud
rates from 1.2 kb/s to 12 Mb/s.
If the desired baud rate is not listed, select User Defined on the Baud softkey;
then, select the desired baud rate using the User Baud softkey. You can set
the user-defined UART baud rate from 100 b/s to 8.0000 Mb/s.
d Polarity — Select idle low or idle high to match your device under test's state
when at idle. For RS232 select idle low.
e Bit Order — Select whether the most significant bit (MSB) or the least
significant bit (LSB) is presented after the start bit in the signal from your
device under test. For RS232 select LSB.
Back
NOTE
In the serial decode display, the most significant bit is always displayed on the left regardless
of how Bit Order is set.