maximum duration of a schengen visa for multiple visits
Once the person departs the Schengen territory, he/she can't enter again without obtaining a new visa. Multiple-entry visa: Allows multiple stays in one or more Schengen countries, as long as the total length of the stay does not exceed 90 days in a given 180 day period from the date of first entry. multiple entry visa is not issued at all the embassies/consulates. If the validity of the visa is over while visiting the Schengen territory, the person can no longer stay in the Schengen territory even if the person has not stayed for 90 days.