Problem with initialization of a shift register on while loop

[Graymalkin79]

I have posted previously regarding this issue and part of the solutions I received worked. I have initialized the shift register on my main while loop, but I also have an additional while loop with shift registers that is contained within this main loop. I have tried to place a constant outside of all the while loops to initialize the internal register, but the zero remains throughout the execution of the program.

It's odd that the program is doing this b/c I thought that if I placed the constant outside of all the loops, then it would only pass the zero along one time when the program is executed. I need to have the values in my inner loop passed along to one another so that I can perform a summ
ation on my calculations. I have attached my VI from LabView 4.0 with the error causing zero constant attached to the while loop. If you have version 6, you have to open it from within LV. You can't doule click on it for some reason.

It seems like an easy fix, but I can't figure it out without having to change my entire setup!

[Lab Viewer]

I opened your VI in LV6 but I don't see any value going to the shift register located on the right side of the loop. Assuming that it's not a LV4/6 compatibility problem, you have to wire the updated value to the shift register containing an arrow pointing up in order to have this value available in the next step (You can take a look in lv folder\examples\general\structs.llb to find some examples on shift registers - I hope it's the same in LV4).
Let me know if I didn't understand the problem.

[Doug (CapeFl)]

Lab Viewer, apparently you could open the VI, I'll have to see what's wrong with my browser. But, from what you say, that should be the solution, else his loops keep getting the same data into them - a zero, versus updated data.

[Doug (CapeFl)]

When I try to open your VI, it appears to be a Text file. ??

[JeanPierre]

Of course... the VI file has a .txt extension!
Save on file and change it to .vi or open from LabVIEW

Jean-Pierre

[Doug (CapeFl)]

Thanks - its always the obvious that gets...

[Gorka Larrea]

The problem is (as you can see if you run the vi with the lightbulb on), that the inner shift register is initialized with zero every time, so the sollution is to pass the initialize the shift register with other shift register in the outer loop, and initialize this one with zero value. This way i think you'll get what you want.
Hope this helps

[Graymalkin79]

Gorka, you have the right idea! Unfortunately, when I tied the constant zero that is attached to the outer loop shift register to the inner one, it would still constantly initialize the s.r.

Also, sorry for the issue of the text file. If you show "all files" in LV 6 open file dialogue, you can select the VI and it will open it without having to do any conversion.

[Gorka Larrea]

Did you try it like this? It shouldn't initialize the outer s.r. every loop.
Sorry but i don't have DAQ installed, you'll have to fix the vi to work.
Hope this helps

[Graymalkin79]

OK, I see now. I'll check this out in the lab tomorrow and see what happens. I think it will work, but I'll keep all of you posted. Thanks for all your help! Without this forum, I would be at a total loss as to find my way around LV.