Sets or gets whether the time container must synchronize playback to this element.
One of the values in the Property Values section.
The value for syncMaster can be set only as an attribute. The associated property is read-only and cannot be set by script.
This property supersedes the clockSource property.
Two elements that share a common parent, with a locked relationship, cannot act as syncMasters in a single document tree.z
In this graphic, T4 and T6 can be syncMasters, as long as T1 isn't locked. See syncBehavior for more information on locked elements.