Explanation:

The TimeSensor serves as clock which sends out events every so often. In our case, since we set cycleInterval to 0.2, the clock will send a message out every 0.2 seconds (approximately). TimeSensors remain inactive until startTime is reached. If loop is TRUE the TimeSensor will run either until stopTime is reached, or forever if stopTime < startTime. In our case since loop is TRUE, stopTime is fixed at -1 and startTime has a default of 0 this TimeSensor will genereate events forever.