How do I set up DAQ Assistnat to acquire fewer than 65,000 data points

[Bill_5335]

Here's is what I am trying to do.

     Acquire data and save to a Labview measurement file so the file can be opened by Excel

     The data is acquired over a 10 minute period.

What works.

     I can acquire the data ( four channels)

     I can save it to a Labview Measurement file.

     I can open the data in Excel

What my problem is:

    Excel can only display 65,000 lines of data.

    When I open my file in Excel, Excel cuts off anything after 65.000 lines.

    I really don't understand how the "Data Acquisition" modes function in the DAQ Assistant.

         When I select "1 Sample"  I get a message to specify "sample clock rate"

         I don't know where/how to specify the clock rate.

How can I configure DAQ assistant to collect the data over a 10 minute period that has less than 65,000 lines of data so I can open the data in Excel?

Bill

How can I set up

H

     My Vi collects more than 65,000 lines of data.

[ABCPrograms]

Hi Bill,

This is a document a used a lot when starting to work with DaqMX, hope it helps for you as well.

That beren said, there a different way to collect data from a analog input.  Contiuous or single sample.

Two of the most important parameters of sampling is :

- sample rate

- nr of samples

If you're reading continuously, you "VI" will read a number of samples from your card with the sample rate you specified.  This takes of coarse a certain amount of time.

If you know what the sample rate is : e.g. 5000samples/sec

and you know the max amount of samples you want : 65000 samples

=> you know exactly how long your sampling shoudl take : 65000/5000 = 13 secs

All depends on the sample rate 😉

if you're talking about taking samples in a 10 minute time base and you want max 65000 samples => 65000samples/600secs => 108.33 samples/sec

This can be configured with the Snippet found below.

1. create a task

2. Create a channel

3. Daq mx timing

4. start task

5. read data

6. Stop task

7. Cleanup task

Hope this helped

[Bill_5335]

Bjorn,

Thanks for the help.

I think I need to state my question better.

    How do I configure my DAQ Assistant to acquire one sample per loop?

    If this is done by "Specifying the Sample Clock Rate", How do I set this rate?

    I only need to acquire 5 or 10 samples per second.

Bill

[ABCPrograms]

Bill,

you can see the timing VI in my snippet?  That is where you can set the samplerate.  Sample rate is the amount of samples you want get from you analog in per second.  In your case 5-10.

How long does 1 loop take?  100ms?  1s?  depending on that time, you can determine the number of samples you want to read.

If you don't want to read finite samples, just set it to contiuous and place the read VI in a loop.  Add a shift register an bundle the outputs in an array.

Those are the two ways to go.

Here is a continuous example.

[ABCPrograms]

Bill,

If you use a daq assistent and configure it, afterwards you can right click on it and open front panel.  Then it is transformed into a VI where you can change what you need.

You can enter the number of samles you want to read in each cycle (1) and the frequence (samplerate 10/s)

Below is a print screen of the timing in DAQ assistant.