I assume you mean that you mean that you want to display the data while the subVIs are running and not how to return a value from a subVI. What you need to do is in each subVI, write to a reference of the indicator on the main. I've attached a simple example. There are other shipping examples on references. To create a reference, right click on the indicator on the main's front panel and select Create>Reference. Then, find the reference on the block diagram and select>Create Control. Cut the control from the main's front panel and paste it on the front panel of your subVI. Wire this reference to the subVI's connector pane. On the subVI diagram, right click the reference and select Create>Property>Value. Wire the reference to the property's reference input and wire the value you want to pass to the main to the property's value input. On the block diagram of main, wire the reference of the front panel control to the subVI.
Now that I've said that, I'd also like to second Uwe's recomendations. While the procedure above makes it possible, it's usually not necessary. I find it simpler to just show the front panel of a subVI while it's running. It most cases, the main VI can't do anything with the data until the subVI finishes anyway.
Message Edited by Dennis Knutson on 06-22-2005 09:08 AM