Question

I have a numeric control( not Indicator) and a for loop(limit 5)

I need to display the [current loop Index+ value in the numeric control] in the Numeric control. I’m new to LabVIEW. Is there any idea to do this?

Answer 1

To write a value to a control, you need to create a local variable from it (right-click on the control’s terminal on the block diagram and choose Create > Local Variable). To have it update each iteration of your For loop, put the local variable terminal inside the For loop and wire whatever you want displayed to that terminal. I’m not sure if this is going to be a good user interface design, but it’s the answer to your question.

You can also use local variables to write to indicators from more than one place in your block diagram, and to read from indicators or controls. You can have more than one local variable terminal for any given control or indicator. Each local variable terminal is either for reading or writing – right-click on the local variable and choose Change to Read or Change to Write.

You should be careful about using local variables to pass data around, because program flow will no longer be controlled by data flow as it is when you pass data along a wire, and this could give you unpredictable behaviour (race conditions). Writing in one place and reading in multiple places is OK if the readers only need to know the current value at the time they execute, and so is writing to an indicator from multiple places where the indicator is only being used to display information to the user.