Parameters: V: Amplitude of source voltage trapezoid (default value = 1 Volt) rising: Length of rising time of trapezoid to be generated (default value = 0 sec) width : Length of on state of trapezoid to be generated (default value = 0.5 sec) falling: Length of falling time of trapezoid to be generated (default value = 0 sec) period: Length of period of trapezoid to be generated (default value = 1 sec) nperiod: Number of periods of trapezoid to be generated an infinite number of periods is being generated if nperiod < 0 (default value = -1) offset: Offset of trapezoid to be generated (default value = 0 Volt) startTime: Start time of trapezoid to be generated (default value = 0 sec)