concatenating 2D arrays

[sundas]

Hello, i am acquiring a 2D data from DAQ. Data Rate is 10MS/s and number of samples are 5MS/s. Means dt is 0.5 sec. I am using while loop to acquire data. i want to concatenate two consecutive frame to process. i used shift register and stacked shift register but it only saves 5MS/s. For the stacked shift register i add element on left side but it didnot work. secondly, i used build array with concatenate inputs. when i saw its out output (10M samples) in a graph i see a discontinuity at 5M samples. can anyone help? my Labview is 2020 64-bit system is dell i-7 Ram=16GB Thanks

[billko]

While your description is detailed, I am having problems trying to visualize the code.  It would be best if you could share the VI (and not just a picture of it).

[altenbach]

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@sundas wrote:
Hello, i am acquiring a 2D data from DAQ. Data Rate is 10MS/s and number of samples are 5MS/s. Means dt is 0.5 sec. I am using while loop to acquire data. i want to concatenate two consecutive frame to process. i used shift register and stacked shift register but it only saves 5MS/s. For the stacked shift register i add element on left side but it didnot work. secondly, i used build array with concatenate inputs. when i saw its out output (10M samples) in a graph i see a discontinuity at 5M samples. can anyone help? my Labview is 2020 64-bit system is dell i-7 Ram=16GB Thanks

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We need to see the VI, because your description makes no sense:

• "MS/s" is a data rate, but not a unit for "number of samples".
• The use of a "Shift register" sounds OK, but a "stacked shift register" is typically not a great solution. Which one is it? Why both? How do they interact?
• What do you "save" where?
• Where exactly is the left side of a stacked shift register? Is that before the loop?
• What do you "add" there? Addition is a well defined mathematical operation.
• So you are sending 10M samples to a graph that is maybe 1000 pixels wide? Seems unreasonable.
• How does the "discontinuity" look like? (some missing sample? large gaps? noise? step?)
• etc.

[sundas]

hello,

1. MS/s means Mega Samples per second

2. Stacked shift register is on left side of data capturing loop.

3. For the DAQ i am using the ADLINK card. if i post the VI you will need that card to capture the real data.

4. "Save" means storing the frames. i tried to store 10M samples using stacked shift register but it only stores 5M samples.
5. "Add" means to use the shift register as a stacked shift register we need to add element on the left side of the loop.i am attaching the screenshot for reference. this is not my code but just to give you idea.
6. About the pixels, yes it is 1000 milisec data
7. for visualizing the discontinuity in samples i am attaching some random example pic. It looks like a step discontunuity.

[AeroSoul]

So you receive 10 million samples per second, but only half of those are unique?

You should still post your code, just save some example data as a default value (or provide a separate file with those values). If the problem is in your code, we could still help.

The discontinuity seems to be in amplitude, which is 2 units lower than the rest of the graph and then returns to normal values.

[sundas]

A breakthrough..!!

i review my application and came up with the conclusion that 7Mega samples (5M of current frame and 2M of previous frame)  will be enough for my processing.

For this, i used build array with concatenate inputs and it works perfectly without data discontinuity.

BUT...!!!! when i pass this concatenated frame to Enqueue, again the data starts missing or discontinuity is seen.

I am using Enqueue VI in capturing loop and i Dequeue it in another loop where this frame will be processed.

Now suggest something.

[AeroSoul]

I suggest you post your code...