Iterative addition of 2D array using a shift register

Hi
I'm trying to add 2D array iteratively using a shift register.
However, the indicator for the output of 2D addition shows nothing.
Do you know Why? and How to fix this problem?
Thx
hiyang

Ok, looked at ur attached VI
You are not getting any output because, you are adding an array with an empty/blank array
First, initialise an array of zeroes of required size and pass it to shift register, Initialise your other array which u are adding inside the loop also of similiar dimension, and later, keep changing its elements
Do as shown in modification of your attached VI
Regards
Dev
Attachments:
2DArray_shiftRegister.vi ‏30 KB

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Hi guys,
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Attachments:
comparesettings.vi ‏32 KB

Use of shift register and similiar C code

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Build 1D array using for loop

Hi guys,
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Nextal wrote:
I am testing out array. How do I create a 1D array of x-y using for loop?
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I am writing a FPGA VI with module cRIO 9104, I need to do a lot of parallel execution of inside a timed loop. In total, I have used 20 pairs of shift registers in the timed loop, which simply means there is 20 parallel exceution across ONE time loop. However, it tells me that there is an over-used of the FPGA resources in the compliation report. One is the Slices and the other is the number 4 of LUTS ( see the attached file), would the compile will be sucessful if I change it to ALL block diagrams cascaded in series without using any shift register accross the timed loop? And do you think that it is reaosnable to have 20 pairs of shift register arranged in parallel inside a timed loop.
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Attachments:
afternoon912.jpg ‏2305 KB

Your compilation report has 2 useful numbers to help answer your question, I'll summarize:
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Is there a routine one can use to shift the column of data by one each time the loop index increments? In other words, increment the columns that the data is being saved by using the index?

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Attachments:
visual.vi ‏34 KB

tombech wrote:
[...]The reason why I don't want to use the shift register or feedback node is due to speed[...]
Tommy,
shift register are the fastest you can ever get...........
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CEO: What exactly is stopping us from doing this?
Expert: Geometry
Marketing Manager: Just ignore it.

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JWJ wrote:
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How to use Shift Register?

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Today I spend hours to ficure out how to use a shift register with labview.
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ShiftRegister1.vi ‏23 KB
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Hi
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Writing data to spreadsheet in FOR loop without shift register

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illustration22.JPG ‏52 KB
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An Action Engine can thought of as an encapsulated shift register.
AE's out-perform locals while alos elliminating possible race conditions. You may want to review the Nugget I wrote on Action Engines.
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Shift register versus comparison in while loop

Hello,
I have a question regarding the "proper" (i.e. cheaper in terms of system ressources, easier to read, etc) way of testing the first entry in while loop. One way would be by using a shift register another by detecting if the loop iteration is zero (see the exemples attached here). I am doing some calculations in this loop, typically 300 iterations or so.
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Attachments:
while_loop1.png ‏54 KB
while_loop2.png ‏53 KB

Express vi's are not entirely evil. And the time delay express vi's are harmless. I have found express vi's to be very useful if I'm trying something new. Besides, once you get everything working the way you want it to you can always open the front panel and clean out any extraneous code that might slow things down. Once you have done that it will perform just like you wrote it yourself.
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Questions about shift register

hello!When I use the shift register，A problem occur！what I want to use is the serial in shift register function，But found only use parallel shift register，someone can give me any suggestions？(The best way has an example of a serial shift register),thanks!!!
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I want to achieve ：Each element of the array in the shift register Compare with 5，If less than 5, the output is 1, otherwise 0；but as you can see the vi is wrong ;Error reason is because of the shift register only for computing the entire array but not Single element，any suggestion?
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the vi.png ‏8 KB
array.png ‏5 KB

How to program shift register to read only when a new user is detected from user?

Hi,
I'm currently developing a program for position control in labview. The program is quite simple, whereby user will input the distance that he wants the table to be in the labview program, and labview will send signal to move a motor that will turn a ball screw to move a table horizontally to the targetted position. The criteria is that the profile of the motor depends on the distance it needs to move, whether a two-phase (acceleration and deceleration) or three-phase (acceleration, constant velocity, deceleration) to reach the target position.
The problem occurs when the user wants to enter a new position (second input) for the table, as the input by user is position the table needs to be but the input required to determine which profile the motor follows depends on the distance that the table will move to get to the targetted position. Therefore, I would need a function to store the input by user temporarily, and recall it only when a new input from user is detected. By this, I would be able to use the difference of the input (input [n+1] - input[n]) and feed it to determine which profile the motor follows and the input by user can be kept as the position he wants the table to travel to (to compare with encoder).
I thought of using shift registers to do this, but I am not able to make it to perform the deduction ([n+1] - [n]) only when it detects a new input. When i try using shift register, it travels to the targetted position, and one it reaches it will travel back to the original position. For example, when a user input 90, it means the table needs to move to point 90. As the shift register is initialized to 0, it will move to point 90 (90-0 = 90) but upon reaching 90, the shift register sends a signal of 90 (90-90 = 0) and the table returns to it's initial position.
Is there any way that I can delay the reading of shift register only when a new input is detected or is there another way for me to achieve what i want?
I've tried searching the discussion forum and ni website but couldn't find similar problems. Thanks for your help in advance.
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Go to Solution.

Hi,
I've managed to get what I needed by using a shift register + event structure as suggested by Adnan. However, I face another problem after implementing SR+event. I've attached two files, first the original program and second the updated program using SR + event. (it's only the jpg file as I've forgotten to save the labview program, will upload the program by tomorrow.
In the original program, I have an elapsed time that is able to run continuously when I run the program. In the updated program, my elapsed time don't seem to run continuously when I run the program (as shown by elapsed time indicator). I need the elapsed time to run continuously as a input to calculate my motor profile.
I suppose this is caused by the introduction of the event structure, will adding a case structure to wrap the event structure solve the problem or is there another way to get pass this. Appreciate if someone could drop me a pointer or two.
Thanks
Attachments:
Mar 16 - continuous elapsed time.png ‏12 KB
Mar 16 - elapsed time not continuous after introducing shift register + event structure.png ‏17 KB

Iterative addition of 2D array using a shift register

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