Scientific SMO1000A-S, User Manual

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User Manual SMO1000A-S
99/176
UART/RS232 Triggering and Serial Decode
Please order “ Setup for UART/RS232 Signals”, “UART/RS232Triggering” and
“UART/RS232 Decode” to trigger and decode the signals.
Setup for UART/RS232 Signals
To set up the oscilloscope to capture UART/RS232 signals:
1. Press Decode on the front panel to turn on the DECODE function menu.
2. Press Serial and select the desired slot (Serial 1 or Serial 2).
3. Press Decode option and select UART/RS232 with the Universal Knob , and then
push down Universal Knob to confirm.
4. Press the Signal softkey to enter the UART/RS232 SIGNAL menu.
Figure 47 UART SIGNAL Menu
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 to select the channel for the signal.
c. Press the corresponding Threshold softkey; then, turn the Universal 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.
6. Press the UP softkey to return to the DECODE menu.
7. Press the Configure softkey to open the UART/RS232 BUS CONFIG menu. Set the
following parameters.
Figure 48 BUS CONFIG Menu
Baud — Press the Baud softkey, then press the Universal Knob and select a
baud rate to match the signal in your device under test. If the desired baud rate is
not listed, select Custom on the Baud softkey, and then press the Custom
softkey and turn the Universal Knob to set the desired baud rate. You can set
the UART baud rate to 115200b/s at most.
Parity Check — Choose odd, even, or none, based on your device under test.
Stop Bit
—Set the number of stop bits in the UART/RS232 words to match your
device under test.
Data Length — Set the number of bits in the UART/RS232 words to match your
device under test (selectable from 5- 8 bits).