When the model has multiple objectives, this attribute is used to query or modify the constant term for objective $n$.
You set $n$ using the ObjNumber parameter. Note that when ObjNumber is equal to 0, `ObjNCon` is equivalent to ObjCon.

The number of objectives in the model can be queried (or modified) using the `NumObj` attribute.

Please refer to the discussion of Multiple Objectives for more information on the use of alternative objectives.