Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs
4
3000 X-Series Oscilloscopes Advanced Training Guide
89
30
Push the horizontal position/delay knob to re- position the trigger point
back to center- screen.
31
Set the scope’s timebase to
200.0 ms/div
.
32
Press the
[Search]
front panel key.
33
Press the
Search Edge
softkey; then select
Serial 1 (UART/RS232)
.
34
Press the
Search for
softkey; then select
Rx or Tx Parity Error
using the
Entry knob.
The white triangles near the top of the waveform area mark the time
location of each “found” occurrence of our search operation as shown in
. These frames are also marked in orange in the first/pointer
column of the lister table. Your scope should have found and marked 4 or
5 occurrences of this search operation based on a total acquisition time of
2 seconds. Note that the number of “found” events is indicated near the
bottom of the display. To automatically navigate to each parity bit error,
press the
and
front panel navigation keys.
Let’s now set up the scope to trigger exclusively on parity errors. But
because these errors occur so infrequently, we will need to change the
trigger mode from Auto to Normal to prevent auto triggering.
35
Push the horizontal position/delay knob to re- position the trigger point
back to center- screen.
36
Set the scope’s timebase to
1.00 ms/div
.
Figure 63 Using the scope’s automatic Search & Navigation capability to find all
occurrences of parity bit errors over a 2 second time span.