V1 Starting voltage for pulse V2 Second voltage for pulse TD Time delay. Voltage will remain at V1 until this specified time. TR Rise time. Time required to reach V2 from V1 (Rise time must not equal to zero). TF Fall time. Time required for voltage to change from V2 to V1 (Again, fall
time must not be equal to zero). PW Pulse width. Amount of time pulse remains at V2. PER Period of pulse. How often pulse actually repeats itself