mike mcfarlane <mike.mcfarlane@virgin.net> wrote in message news:FLo2JH.GwJ@lugnet.com... (...) try (...) zero (...) mode. (...) I think your problem is that the RCX zeros the sensor when you execute the SetSensorType even if it is already that (...) (25 years ago, 23-Nov-99, to lugnet.robotics)