Signal with Jitter VI

Owning Palette: Signal Generation VI

Requires: Jitter Analysis Toolkit

Creates a clock or data stream signal waveform and injects jitter into the signal. You can use this VI to create a waveform with which to test applications that measure jitter.

Examples

	reset specifies the initialization of the internal states. The first time this VI runs, or when reset is TRUE, the internal states initialize to zero. If reset is FALSE, this VI sets the internal states to the final states from the previous call to the VI. The default is FALSE.
	amp noise, if TRUE, specifies to add amplitude noise to the signal in the form of Gaussian-distributed, pseudorandom pattern. This VI uses the Gaussian White Noise VI to add amplitude noise.
	amplitude levels sets the mapping of low and high logic levels to amplitude values. high value is the amplitude for a high logic value. The default is 1. low value is the amplitude for a low logic value. The default is 1.
	sample settings controls the duration, frequency, and sample rate of the waveform you want to generate. duration (s) specifies the duration of the waveform you want to generate. This VI returns the actual duration and number of samples of the waveform in signal info. fc (Hz) specifies the clock frequency in Hz. sample rate (S/s) specifies the sampling rate for the signal in samples per second.
	signal type specifies the type of signal you want to this VI to generate. 0 clock - square (default)—Create a clock signal whose cycles are square. 1 clock - sine—Creates a clock signal whose cycles are sinusoidal. 2 clock - wavetable—Creates a clock signal in which each cycle shape is determined by the wavetable input you specify. 3 data signal—Create a signal that streams the repeated sequence of bits in data stream.
	random jitter controls the Gaussian random components of the period jitter you want to inject. random jitter specifies the mean and standard deviation of a Gaussian noise component. When random jitter contains multiple elements, this VI applies the period jitter you specify to cycles in a repeating pattern. mean (s) is the mean of the Gaussian noise component. std rms (s) is the standard deviation of the Gaussian noise component. random seed controls the seeding of the random components. When random seed is greater than 0, LabVIEW reseeds the noise sample generator. The default is –1.
	deterministic jitter is an array of clusters whose elements are the parameters for each sine tone that is added to form the deterministic jitter to inject. frequency specifies the frequency of the sine tone in hertz. amplitude specifies the amplitude of the sine tone. phase specifies the initial phase of the sine tone in degrees. The default is 0.
	ISI and DCD controls the simulated channel and duty cycle distortion. channel filter introduces inter-symbol interference into the waveform. bandwidth is the bandwidth of the channel lowpass filter, in normalized units of cycles/sample. The default is 0.5, which disables the simulated channel. type selects the type of filter to use in simulating a channel response. 0 IIR (default)—Specifies to introduce nonlinear phase delays. 1 FIR—Specifies to generate linear phase with pure time delay. DCD (s) introduces duty-cycle distortion (DCD) into the waveform. A positive value compresses the amplitude of the low range of the signal, thus introducing positive DCD. A negative value compresses the high amplitude portion of the signal, thus introducing negative DCD. The default is 0.
	wavetable contains one cycle of a custom clock waveform when signal type is clock - wavetable. The simulated clock signal linearly interpolates through cycles of this wavetable, where a range of [–1, +1] is mapped to the [low value, high value] settings specified by amplitude levels.
	data stream contains the sequence of bits that LabVIEW repeats to construct the waveform when signal type is data signal. Zeros represent low logic values in the signal and ones represent high logic values.
	waveform is the resulting waveform. t0 returns the trigger time of the waveform. dt returns the time interval in seconds between data points in the waveform. Y returns the data values of the waveform.
	signal info returns the duration and size of the resulting waveform. duration (s) returns the actual duration, in seconds, of the waveform. samples returns the actual number of samples in the waveform.
	PJ metrics returns characteristics of the periodic jitter in the waveform this VI generates. PJmin returns the amplitude of the tone with the smallest amplitude from periodic jitter. PJmax returns the amplitude of the tone with the greatest amplitude from periodic jitter. PJmean returns the average amplitude of tones from periodic jitter. PJrms returns the root mean square of tones from periodic jitter.

Examples

Refer to the following VIs for examples of using the Signal with Jitter VI:

• Simulated Signal with Jitter VI: labview\examples\Jitter Analysis\Jitter Measurements
• Rj Dj Separation VI: labview\examples\Jitter Analysis\Jitter Measurements