National Instruments NI PXI-6541 用户手册

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6. Enter values for the generation and acquisition voltages in the controls 

below the Clock Frequency control. You can choose from standard logic 
families (NI 654X/655X) or enter High and Low values to create your 
own custom levels (NI 655X).

7. Choose a fill pattern. The following figure shows the pattern control and 

the first few signals in the window.

When generating a Marching Ones or Marching Zeroes 

waveform, it is convenient to make the waveform size a multiple of 
the number of selected channels.

8. Click Play to generate the pattern shown in the graph on the selected 

channels. The default generation option is Continuous, but you can 
toggle this setting using the control below the graph.

The Play and Stop buttons are shown in the following figure.

Because the data channels on the NI digital waveform generator/analyzer 
are bidirectional, while the data is being continuously generated on all of 
the channels, as in the previous step, you can acquire the data being 
generated.

Refer to the specifications for your device for information on 

the setup and hold times and propagation delays associated with 
generation and acquisition operations. At some frequencies, 
generating and acquiring data on the same channels when no cable 
is attached to the DIGITAL DATA & CONTROL (DDC) connector 
violates these timing parameters and results in incorrectly sampled 
data. For information on proper signal acquisition, refer to the 
NI Digital Waveform Generator/Analyzer Help.

To acquire the pattern, complete the following steps:

1. Click the Acquisition tab.

2. Click Play. The device acquires the digital data that you generated in the 

previous steps, and the data is displayed on the graph.

3. Click Close when you are finished.