Line grouping in data acquisition

[Manik981211]

What is the difference between one channel for each line and one channel for all lines selection in line grouping for daqmx create channel digital output.

[santo_13]

Determines how you write data to DAQmx Write API

[Manik981211]

Can you please give detailed explanation with example

[GerdW]

Hi Manik,

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@Manik981211 wrote:
What is the difference between one channel for each line and one channel for all lines selection in line grouping for daqmx create channel digital output.

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Drop a DAQmxWrite function in your block diagram and look at those 6 options you have when selecting Digital->Multiple Channel->Single Sample->"...". Now think about how "one channel for each line"/"one channel for all lines" relate to those options!

When handling multiple digital channels I prefer the "port" options...

[Manik981211]

Actually I can understandthe single channel>single sample. But I am unable to relate this with line grouping. Can you tell in what occasion I have to choose one channel for all lines and one channel for each line with some example and Discrription Thanks in advance

[GerdW · Accepted solution]

Hi Manik,

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@Manik981211 wrote:
in what occasion I have to choose one channel for all lines and one channel for each line with some example and Discrription

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"One channel for each line" relates to using boolean arrays, with one element per channel.

"One channel for all lines" relates to using U8/16/32 data, with each bit in the unsigned integers relating to one digital channel.

You don't "have to", but you "can" choose which datatype suits your requirements. Keep in mind: using boolean data in LabVIEW will increase memory requirements (8 times) as each bit is stored/handled in memory as a byte. Using unsigned integers is more memory efficient, but you need to learn how to set/reset single bits in those U-INTs…

[Manik981211 · Accepted solution]

I tried to find the difference between digital 1d and 2d boolean n channel 1 sample in labview help, I noticed each channel in the task can contain 1 digital line(1d) and the channel contain one or more digital lines(2d). But when I simulate this two, it seems to be work like same.can you explain why?. And also I didn't get any error.

[Manik981211]

I understand the concept. Thanks