EASY! Labview Race Condition

Question

I'm very new to LabVIEW... I need to write a simple program in LabView to update the value of an encoder.

Long story short... In a loop, I need to manipulate variables in this order:

How do I prevent accidentally storing the old value before I calculate the new value?

Thanks in advance.

Are you monitoring whether the value changes? Add one more variable `New Value2`, assign `New Value2 = New Value` before doing `1.New Value = Old Value + Current Value`, then compare `if (New Value != New Value2)`, then do step 2. But I am wondering how could that happen if it is skipping step 1 and jump to step 2 if you are not talking about value changes — LONG, Jun 28 '17 at 17:48
*face palm* This will probably fix it thank you. It's not skipping step 1, they just both happen at the "same" time, so sometimes its equivalently computing new value = new value + current value. — heyjaynell, Jun 28 '17 at 17:52
Correctly programmed that should not be possible. Can you show your labview code? — D.J. Klomp, Jun 28 '17 at 21:22
that "EASY!" caught me off guard, I'm lmao right now hahahah. — LucasJ, Jun 02 '22 at 20:23

score 1 · Accepted Answer · answered Jun 28 '17 at 21:35

What you want is to pass the old value via a shift register (or feed back node, is the same). Here is the code snippet that shows you how to do it:

You can check that it works by looking at the New and Old values array.

A side note since your new, you can import code snippets directly into labview.

1 Answers1