98
4000 X-Series Oscilloscopes Advanced Training Guide
4
Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs
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
Tap the
Search Edge
softkey; then select
Serial 1 (UART/RS232)
.
34
Tap the
Search for
softkey; then select
Rx or Tx Parity Error
.
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.
Figure 63
Using the scope’s automatic Search & Navigation capability to find all occurrences
of parity bit errors over a 2 second time span.
