Best Practices for Data Acquisition with LabVIEW - Emmanuel Katto Uganda

[emmanuelkatto]

Hello NI Community,

My name is Emmanuel Katto. I’m currently working on a data acquisition project using LabVIEW, and I’m seeking some advice on best practices. Specifically, I have the following questions:

1. What are the recommended techniques for optimizing data acquisition rates while ensuring data integrity?
2. How can I effectively handle multiple channels of data in LabVIEW without causing performance issues?
3. Are there any common pitfalls I should be aware of while implementing data logging and analysis in my project?

I appreciate any insights or resources you can share to help me improve my approach.

Thank you!

Best regards,

Emmanuel Katto

[dsb@NI]

Learn LabVIEW: Getting Started, Tutorials, Training
Learn 10 Functions in NI-DAQmx and Handle 80 Percent of Your Data Acquisition Applications

Refer to the installed DAQmx examples!

1. Get something working by starting from an example.
2. Evaluate performance before trying to optimize.
3. Iterate and test in short cycles so you don't get caught trying to debug multiple changes at once.

When you post back, post a specific question (to a new thread).
Help us help you by including:
what you have tried

where you are stuck
your code and data files

[mcduff]

First post some code or pseudo code. In addition, describe the system you are using/envisioning. For example, a USB DAQ is different from a PXIe DAQ.

I assume you are using NI-DAQ equipment; for NI-Scope the advice may be different in spots.

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1. What are the recommended techniques for optimizing data acquisition rates while ensuring data integrity?

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• Use the built in logging feature of DAQmx, do not write your own unless you want to save processed, not raw data.
• Read about 1/10 of your sample rate with each DAQmx Read Function.
• If the data rates are large, the number of samples to read should be an even multiple of the disk sector size that is close to the previous built of 1/10 the sample rate.
• Display the data in a separate loop. In addition, decimate the data before displaying
• Any analysis should be done in a separate loop.

How can I effectively handle multiple channels of data in LabVIEW without causing performance issues?

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The previous bullets apply

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Are there any common pitfalls I should be aware of while implementing data logging and analysis in my project?

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Need to describe your application first before answering. But a general answer would be a loop for DAQ, a loop for display, a loop for analysis.

[Steffen01]

start with, how much data do you need and not how much you can get

what data

how often

where to store

who will analyse

do you need timestamps

In my project I get away with 200 values / channels in 1 second intervals, very easy. Put into SQL server, kind of simple to analyse