Error - 200141 occurred at Counter - Read Pulse Width and Frequency (Continuous).vi

[cthunterMC]

Understood. I've now got sample rate working. My last question is how to overcome the1048576 row limitation of excel? Any thoughts? I need to take 250ksamples/second for 10 seconds (2.5mil samples). Thanks.

[Kevin_Price]

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@cthunterMC wrote:

Understood. I've now got sample rate working. My last question is how to overcome the1048576 row limitation of excel? Any thoughts? I need to take 250ksamples/second for 10 seconds (2.5mil samples). Thanks.

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Sure.  Don't limit yourself to Excel.  I know it sounds flippant, but it's also reality.  If Excel can't handle your data set, you've got to use something else for your post-processing.  Maybe even LabVIEW itself since you've already got it and it can handle 2.5 million samples with ease.

-Kevin P

[cthunterMC]

I'll look into that. My VI is now working great with static delay, however, I am now testing dynamic delay. I need to measure this in nanoseconds and the Two Edge Separation task resolution minimum value is in microseconds. In the units setting of this task, the available selections are seconds, ticks or custom units. Is there a way to manipulate seconds or custom units to achieve greater resolution?

[cthunterMC]

I found using tdms instead of excel generates the resolution I need. 

So here we are (see attached).

The last remaining (hopefully) issue is sample rate. I get an accurate sample rate only if the "write measurement file" subvi is outside the while loop. The problem with this is it only samples the last data point. 

[cthunterMC]

Here's the alternative with timing inside the while loop.

[Kevin_Price]

I don't see anything like an accurate "sample rate" in either situation.  Please re-read my msg #5 and #10.   Under Implicit Timing, the external signal defines the rate at which samples are captured, not anything you can enter on the front panel or block diagram.  Also, no information about this sample timing is being stored in your file.

What is it you really care about when you refer to the term "sample rate?".   I think it must be something different than the normal meaning of the term.

(Also, I think you're likely going to be better off with an approach more like my msg #10 attachment.  There the task is pre-configured for continuous sampling before the loop and then inside the loop you take readings from the continuously running task.  That's better than your latest mod that reverted to an approach that redefined the entire task from scratch every loop iteration.)

-Kevin P

[cthunterMC]

When I say sample rate, I'm referring to the samples per second control I have on the Counter 4.VI I sent previous. I can enter 1000 samples/seconds and a time target of 4 seconds to achieve 4000 samples ONLY if the  "write measurement file" subvi is OUTSIDE the while loop. If I place the "write measurement file" subvi INSIDE the while loop, then the amount of reported samples is sparatic.

[cthunterMC]

The bottom line is I need continuous two edge separation data points at a rate of 200k samples per second or greater. I also need to plot this data to verify a smooth transition or identify irregularities during the UUT's 5-10 second dynamic delay profile. 

[Kevin_Price]

[delayed reply due to being "off the grid" for several days]

Honestly, I think you're losing the forest for the trees.  In your 2 most recent messages, the first stated a desire to have a 1000 sample/sec rate while the second stated a desire for 200000 (or greater) sample/sec rate.

You don't seem to have understood the things I've said multiple times about "Implicit" timing and how sample rate is up to the signal in question, not anything you can program independently.

The example I posted in msg #10 should be a really good head start toward what you probably want -- have you tried it?  What are the issues?

-Kevin P

[cthunterMC]

"...the first stated a desire to have a 1000 sample/sec rate..."

What I stated was an example of the difference in number of samples reported from Counter4.VI when the WRITE MEASUREMENT FILE is OUTSIDE vs. INSIDE the while loop. If OUTSIDE, I get the correct number of samples based on the samples/second multiplied by number of seconds desired. 

"...while the second stated a desire for 200000 (or greater) sample/sec rate."

The 200K or greater sample rate is what I need as stated in the 7-22-2022 09:57 comment.

I completely understand implicit timing in this VI, but for sake of progress, we will continue to use the VI you posted in msg#10. I've got it attached with notes on the block diagram.

Let me repeat, I need continuous two edge separation data points at a rate of 200k samples per second or greater. I also need to plot this data to verify a smooth transition or identify irregularities during the UUT's 5-10 second dynamic delay profile. I'm almost there with implicit timing, however I would prefer greater sample rate than the frequency of the pulse train as measured by the counter (200kHz).