n = oSequencer.MaxSize
The value -1 represents unlimited number of items. The limitation is suitable to prevent designer's errors when the number of waiting items could increase over all limits.
The value of this property can be also obtained in the "PmaRoot" item of the INFO system (when looking into the object with this property).
var oSequencer = pMe.Pm("/Sequencer");
var nMaxSize = oSequencer.MaxSize;