Check the port specified in [Ei] OS corresponds with the physical port into which the sensor is plugged. Note that ports on the contextual sensor controller are numbered 0 through 7 going left to right.
To avoid the incorrect detection of events, be very careful when connecting sensors to the contextual sensor controller and ensure the connected sensor type matches the registered sensor type in [Ei] OS.
For example, if you connect a traffic IR-sensor to the controller and register it in [Ei] OS as a light sensor with the event Product picked up, you might receive false events detected by the traffic IR-sensor. These events will be counted as a 'product picked up' event, so your data will be inaccurate.