Here is the proper way to setup PPT and Intersense head tracking in Vizard 3.0. If you are not using Vizard 3.0, download it.
Code:
import viz
viz.go()
PORT_PPT = 0 #Com port number. Zero to search through COM1 to COM4
headPosSensor = viz.add('vizppt.dls')
PORT_INTERSENSE = 0 #Com port number. Zero to search through COM1 to COM4
headOriSensor = viz.add('intersense.dls')
headCombined = viz.mergeLinkable( headPosSensor, headOriSensor )
# Link hybrid head sensor to view and don't offset by eyeheight
headLink = viz.link(headCombined, viz.MainView, dstFlag = viz.LINK_POS_RAW)
#add world
viz.add('court.ive')