Keysight 4000 X-Series, Руководство по продвинутой подготовке

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Advanced Triggering, Search & Navigation, and Segmented Acquisition Labs
3
4000 X-Series Oscilloscopes Advanced Training Guide 75
You should now see on your scope’s display a stair-step sine wave on channel-1
plus eight digital waveforms captured by the D0 through D7 digital channels of
acquisition similar to Figure 46 . D0 through D7 are the input signals to an
digital-to-analog converter (DAC), while the stair-step sine wave is the output of
the DAC. At this point, you may be wondering where these digital signals are
coming from. Are they real or just simulated? They are real signals generated by an
internal pattern generator inside the scope. They are then internally routed directly
to eight digital/logic acquisition channels of the scope (D7-D0); bypassing the
parallel logic probe. In a real measurement application such as this, you would use
the logic probe that is supplied with the scope to probe signals such as these.
The scope is currently triggering on the output of the DAC (channel-1) using the
scope’s default Edge triggering mode. We can also set up the scope to trigger on
Boolean pattern conditions based on the input of the DAC (D7-D0), which might
be necessary if the output signal were more complex than a repetitive sine wave.
Let’s now set up the scope to trigger on an input pattern condition = 1110 0110
(binary D7 – D0), which is equivalent to E6 (HEX). Note that this input logic pattern
condition will be coincident with the highest output level of the DAC (positive peak
of the stair-step sine wave).
10
Press the
[Trigger]
front panel key; then select Pattern .
11
Tap the Channel softkey; then select D7 .
Figure 46 Capturing multiple analog and digital signals with an MSO.