Unfortunately, you cannot change that property in run-time. In LabVIEW, you can programmatically change the properties of controls and indicators through the property node. However, this does not mean all properties can be changed at the runtime. Some properties can only be read-only or only settable during editing. You can find this information by searching the property name in the LabVIEW Help. For example, Element Gap? property has the characteristics in which Permissions
and Settable when the VI is running
. This means that you can only set the property in the edit time.