How can a customer use the call button to reach the manager if the line is busy with real time monitoring?
There is a website set up for Versa XS. You can check it along with the frequently asked questions page where you can download PDF guides and manuals for the application.
Official website: https://www.liftmaster.com/For-Businesses/Access-Control-Systems/Versa-XS-4-0
FAQ page: http://liftmaster.custhelp.com/app/answers/list/p/29,305,304,308
You can check for the way the software works using the documents and information on the FAQ page.