Hi,
if you use solar study like this:
you can change the active frame via python:
import clr
clr.AddReference("RevitAPI")
from Autodesk.Revit.DB import *
clr.AddReference("RevitServices")
import RevitServices
from RevitServices.Transactions import TransactionManager
from RevitServices.Persistence import DocumentManager
#The inputs to this node will be stored as a list in the IN variables.
view = UnwrapElement(IN[0])
frame = IN[1]
doc = DocumentManager.Instance.CurrentDBDocument
sunSettings = view.SunAndShadowSettings
TransactionManager.Instance.EnsureInTransaction(doc)
sunSettings.ActiveFrame = frame
TransactionManager.Instance.TransactionTaskDone()
#Assign your output to the OUT variable.
OUT = 0