MATLAB: GUI callback issue.

gui

I want to check in GUI_2 if there is a stored value to update a value in GUI_1 without opening GUI_2. Is there a way to do this? Currently GUI_1 opens GUI_2 when it searches for the information.
Current Code:
function update_values_Callback(hObject, eventdata, handles)
dT = getappdata(deltaT, 'deltaT'):
if isempty(dT)
close(deltaT);
set(handles.deltaT, 'String', '') ;
elseif dT ~ 0
set(handles.deltaT, 'String', dT);
end

Best Answer

No, if GUI_2 is not open then it does not exist to store data. When GUI_2 is not open, it is the imaginary GUI_2.
Note: there is a difference between GUI_2 being open and GUI_2 being visible. A GUI does not need to be visible to check its properties, but it does need to be open.