I have a common switch on two panels.

[liz2]

When a panel is brought to foreward, it should be in control of the switch. When the switch is closed on one panel, it should be closed on the other panel also, so that when that panel is brought foreward, the switch will be in the correct state. Note, even when the vi is not in the foreground, its subvis are continously running. Switches and displays are controlled with bundled refs.

[Aitortxo]

May be your problem can be resolved with Globals. I post an example with globals

SwitchPanelA is the Master Switch. You can change it's value, and SwitchB will change
SwitchPanelB is the Slave Switch.

For both VIs to run, you need a Third one that contains the Global Variable, SwitchGlobal.

Aitortxo.

[liz2]

Thank you Aitortxo, but unfortunately I have Labview 6.1.

[Aitortxo]

Here you have 6.1 Version files

Aitortxo.

1.- Create an VI with a Switch Control (Panel A)
2.- Create another VI with a Switch Indicator (Panel B)
3.- Create a Global Variable (Functions-Global Vble)
4.- DblClick Global Vble, a panel opens, and create a Switch
5.- RightButton in Panel A's BlockDiagram's GlobalVble and Select Switch
6.- Wire Switch Control to Global Vble
7.- Copy-Paste the GlobalVble to the other VI, and wire to Switch Indicator
8.- Run Continuously in both (or create a while structure) and changes in Switch Control will be seen in Switch Indicator