how to direct Virtuoso Visualization and Analysis XL to display all signals in single window/Strip?

hello exports, I had a simple testcase setup in ADE-L with signals to be plotted for a "tran" simulation. when all signals to be plot are analog, they all go to a single waveform window which is fine. but after I convert a few signals as digital by a2d function in ADE-L and re-run the simulation, the signals are now plotted into multiple subwindows. from ADE-L output setup, I don't see any control to direct the signals to be plotted all together or in separated waveform windows. Even I save the setup as Ocean Script, I don't see any directing to multiple waveform windows either. how can this waveform display windows be controlled to plot always in single plot instead I have manually drag them together everytime? thanks, David