Waveform saves to file but only shows 1 data point.

[JAB2019]

Alten, I replied as the same time as you.

- I don't believe I really need to write the column headers because they aren't needed for my project

- I hear you, but I don't understand how that is any different than what is already being done? It already appends each row without headers. What do you mean by using lowlevel primatives?

I need to write this data on the order of milliseconds, not 5 seconds in between each datapoint. When I began all of this, I started with the DAQ Assistant and used it to see if I was getting analog input to the NI 9209. I was able to see all 32 channels in table form and it was quite fast. Now that I've done it myself manually, it's incredibly slow.

[altenbach]

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@JAB2019 wrote:

What do you mean by using lowlevel primatives?.

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If you are using high-level file IO, the file gets opened (an expensive request to the file manager of the OS, checking permissions, conflicts, space, valid file name, valid location, etc.etc.) and closed with every iteration and it has to find the end before starting to append. If the file remains open at the last file position and all that extra work can be avoided.

Here's a simple example:

[JAB2019]

I seriously fear it would take me a week to understand what is happening in that simple example. I don't think I am cut out for this. There has to be an easier way to write this data.

Do you have a snippet for that code? I don't know where to find half of those components in order to even read the context help.

[altenbach]

LabVIEW 2015.

[RavensFan]

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@JAB2019 wrote:

RavensFan, I have a timer in the loop but the DAQmx Read VI is running way too slowly for what I need. I am acquiring data every 5 seconds with 32 channels whereas I was acquiring 5 datapoints per second with 1 channel. Will adding the DAQmx Timing help this? I don't understand why it is running so slowly here. When I use the DAQ Assistant to configure all 32 channels and test them, they all run very fast. I know I am doing something wrong here. What is it?

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I'm sure following an example of a DAQmx in the Example Finder will allow you to run this faster.  I don't believe even your current configuration would run as slow as you say it is, even with the DAQmx create task inside the loop.

I don't know what you've done lately.  The only code I see is a rather simple in the first message.  And that is actually just a picture of code which means we can't try to run it or modify it.  You should attach actual VI's of your most up to date code to get help.