The output of a kitControl -Maximum object in an I/A Series G3 (Niagara) station will go to Nan if any of its inputs are Nan.
TAC I/A Series
I/A Series G3 (Niagara) station using the kitControl -Maximum object
The cause is not known, but is being investigated.
As a work-around, use the minMaxAvg object's Max function. It is in the kitControl / Util folder. The kitControl -Maximum object is expected to be repaired in a later build of G3.