Hello Boris,
I'm a little uncertain about your first question but i
believe it pertains to the manner in which the display updates rather than noise
or jitter in the acquisition itself. In order to control the update mode of a
waveform display you have to use a waveform chart instead of a waveform graph,
I'd recommend you play around with the "update mode" settings that can be found
by right-clicking on the waveform chart and try to find a setting that appeals
to you. Let me know if you can't find a way to get it to display in the manner
you would prefer. If you're really interested in a specific repeating feature of
your data, then using a digital (or analog if your hardware is capable of it)
trigger, as Lynn recommended, to initiate a finite number of samples would
probably be your best bet.
Now, if I understand your second question
properly I take it you're trying to split each channel output from a DAQ
assistant express VI. If you set the convert from "dynamic data type" VI to
format its output as a 2D array of scalars with each row as a channel the output
can be split up using "Index Array" VI's. For three channels I would lay down an
"Index Array" VI per channel and wire the output from the conversion VI to each.
Then create a numerical constant for the "Index (Row)" connector on each "Index
Array" VI and set them to 0, 1 and 2, respectively, to separate the three
channels into 1D scalar arrays. The "Index Array" VI can be found on the
programming functions palette under the array section. Each channel's data can
then be displayed and manipulated independently.
Good luck!
Pavak
Shah
Applications Engineer
National Instruments
Pavak S
Applications Engineer
National Instruments