DSP Sine Wave
Generates a discrete sinusoid.
Description
Unit DSP Sine Wave generates a multi-channel real or complex sinusoidal signal with independent amplitude, frequency and phase in each output channel.
The unit supports floating-point and fixed-point data types with sign (sign bit).
The block generates a valid sinusoidal signal, if the parameter Output complexity is set to Real.
A valid sinusoidal signal is defined by an expression of the type:
,
where
-
- parameter value Amplitude;
-
- parameter value Frequency (Hz) in Hz;
-
- parameter value Phase offset (rad) in rad.
The unit generates a complex exponential signal, if the parameter Output complexity is set to Complex.
The complex exponential signal is defined by an expression of the type:
.
Generation of multichannel outputs
For both real and complex sinusoids, the values of parameters Amplitude, Frequency (Hz) и Phase offset (rad) ( , , and ) can be scalars or vectors of length , where is the desired number of channels in the output. When you specify at least one of these parameters as a length vector , the scalar values specified for the other parameters are applied to each channel.
For example, to generate a three-channel output containing the following valid sine waves, set the block parameters as shown:
-
Output complexity =
Real. -
Amplitude =
[1 2 3]. -
Frequency (Hz) =
[1000 500 250]. -
Phase offset (rad) =
[0 0 pi/2].
Ports
Output
#
OUT_1
—
sinusoidal signal
scalar | vector | matrix
Details
Outputs a sinusoidal signal as a scalar, vector or matrix.
To output fixed-point data types, you must set the parameters to Sample mode value Discrete and for Computation method value Table lookup.
|
| Data types |
|
| Complex numbers support |
No |
Parameters
Parameters
#
Amplitude —
sinusoidal amplitude
Scalar / array of real numbers
Details
A vector of length , containing the amplitudes of the sinusoids in each of the output channels, or a scalar applied to all channels. The vector must be the same length as the vectors specified in the parameters Frequency (Hz) и Phase offset (rad).
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Frequency (Hz) —
sinusoid frequency (for each separately)
Scalar / array of real numbers
Details
A vector of length , containing the frequencies (in Hz) of the sinusoidal signals in each of the output channels, or a scalar applied to all channels. The vector shall be the same length as the vectors specified in parameters Frequency (Hz) и Phase offset (rad). You can specify positive, zero, or negative frequencies.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Phase offset (rad) —
sinusoidal phase shift
Scalar / array of real numbers
Details
A vector of length , containing the phase shift (in radians) of the sinusoids in each of the output channels, or a scalar applied to all channels. The vector must be the same length as the vectors specified in parameters Frequency (Hz) и Phase offset (rad).
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Sample mode —
count mode
Discrete
Details
Only discrete counting mode is realised Discrete.
In discrete mode, the unit can generate a discrete time output signal by direct calculation of trigonometric function or table lookup.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Output complexity —
real or complex waveform
Real | Complex
Details
The type of signal to be generated: Real specifies a real sine wave, Complex sets a complex exponential sine wave.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Computation method —
method for calculating discrete-time sinusoids
Trigonometric fcn | Table lookup
Details
A method by which discrete-time sinusoids are generated: Trigonometric fcn or Table lookup.
To generate fixed-point sinusoids, you must set the Computation method to Table lookup.
|
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Optimize table for —
speed optimise
Speed
Details
Optimises the table of sine values by speed.
When optimising for speed, the table contains elements, and when optimising for memory, the table contains elements, where is the number of input samples in one full period of the sine wave.
Dependencies
To use this parameter, set the parameters to Computation method value Table lookup.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Sample time —
interval between calculation steps
SampleTime (real number / vector of two real numbers)
Details
The sampling period of the sinusoidal signal, . The period of the block output frame is equal to , where is the value of the parameters Samples per frame.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Samples per frame —
counts per frame
Int64 integer
Details
The number of consecutive samples from each sinusoid to buffer into the output frame.
The output of the block is a matrix to with frame period , where is the value of the parameters Sample time.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Resetting states when re-enabled —
state behaviour within the included subsystems
Restart at time zero
Details
This parameter defines the behaviour of the unit *DSP Sine Wave*when an enabled subsystem is re-enabled. The unit is reset to the initial state.
Dependencies
This parameter only applies when the block is DSP Sine Wave is located inside the enabled subsystem, and the parameters of the block are set to States block parameter Enable is set to reset.
| Values |
|
| Default value |
|
| Program usage name |
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| Tunable |
No |
| Evaluatable |
No |
Parameters
#
Output data type —
output data type
Float64 | Float32 | Fixed-point
Details
Specify the type of output data.
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Output fixed-point type —
fixed-point output data type
Data type
Details
Specify the fixed-point output type.
Dependencies
To use this parameter, set parameter Output data type value Fixed-point.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |