When working with Revit server files or Work shared central files the only way to add or update a file in Vault is through the Synchronize with Central command in Revit. There are several options that can be set for adding a new version of the file to the Vault. At any time, the Synchronize on Demand button can be used to initiate synchronization. By clicking the Synchronize on Demand button it will toggle from:
to:
If the button is set to Update on Synchronize when a Synchronize with Central executes, the current version of the Revit file is added to vault. After the update the button automatically toggles back to No Update on Synchronize.