DSP Blockset

Check Signal Attributes

Generate an error when the input signal does or does not match selected attributes exactly.

Library

Signal Management / Signal Attributes

Description

The Check Signal Attributes block terminates the simulation with an error when the input characteristics differ from those specified by the block parameters.

When the Error if input parameter is set to Does not match attributes exactly, the block generates an error only when the input possesses none of the attributes specified by the other parameters. Signals that possess at least one of the specified attributes are propagated to the output unaltered, and do not generate an error.

When the Error if input parameter is set to Matches attributes exactly, the block generates an error only when the input possesses all attributes specified by the other parameters. Signals that do not possess all of the specified attributes are propagated to the output unaltered, and do not generate an error.

Signal Attributes

The Check Signal Attributes block can test for up to five different signal attributes, as specified by the following parameters. When Ignore is selected in any parameter, the block does not check the signal for the corresponding attribute. For example, when Complexity is set to Ignore, neither real nor complex inputs cause the block to generate an error. The attributes are:

• Complexity

Checks whether the signal is real or complex. (Note that this information can also be displayed in a model by attaching a Probe block with Probe complex signal selected, or by selecting Port data types from the model window's Format menu.)

• Frame status

Checks whether the signal is frame-based or sample-based. (Note that Simulink displays sample-based signals using a single line, , and frame-based signals using a double line, .)

• Dimensionality

Checks the dimension of signal for compliance (Is...) or noncompliance (Is not...) with the attributes in the subordinate Dimension menu, which are shown in the table below. SeeSignal Dimension Nomenclature for a description of Simulink signal dimensions. M and N are positive integers unless otherwise indicated below.

Dimensions	Is...	Is not...
1-D	1-D vector, 1-D scalar	M-by-N matrix, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar)
2-D	M-by-N matrix, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar)	1-D vector, 1-D scalar
Scalar (1-D or 2-D)	1-D scalar, 1-by-1 matrix (2-D scalar)	1-D vector with length>1, M-by-N matrix with M>1 and/or N>1
Vector (1-D or 2-D)	1-D vector, 1-D scalar, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar) Vector (1-D or 2-D) or scalar	M-by-N matrix with M>1 and N>1
Row Vector (2-D)	1-by-N matrix (row vector), 1-by-1 matrix (2-D scalar) Row vector (2-D) or scalar	1-D vector, 1-D scalar, M-by-N matrix with M>1
Column Vector (2-D)	M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar) Column vector (2-D) or scalar	1-D vector, 1-D scalar, M-by-N matrix with N>1
Full matrix	M-by-N matrix with M>1 and N>1	1-D vector, 1-D scalar, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar)
Square matrix	M-by-N matrix with M=N, 1-D scalar, 1-by-1 matrix (2-D scalar)	M-by-N matrix with MN, 1-D vector, 1-by-N matrix (row vector), M-by-1 matrix (column vector)

Note that when Signal dimensions is selected from the model window Format menu, Simulink displays the size of a 1-D vector signal as an unbracketed integer, and displays the dimension of a 2-D signal as a pair of bracketed integers, [MxN]. Simulink does not display any size information for a 1-D or 2-D scalar signal. Dimension information for a signal can also be displayed in a model by attaching a Probe block with Probe signal dimensions selected.

• Data type

Checks the signal data type for compliance (Is...) or noncompliance (Is not...) with the attributes in the subordinate General data type menu, which are shown in the table below. Any of the specific data types listed in the Is... column below can be individually selected from the subordinate Specific data type menu.



General data type	Is...	Is not...
Boolean	boolean	single, double, uint8, int8, uint16, int16, uint32, int32, fixed-point
Floating-point	single, double	boolean, uint8, int8, uint16, int16, uint32, int32, fixed-point
Fixed-point	fixed-point	boolean, uint8, int8, uint16, int16, uint32, int32, single, double
Integer	Signed integer int8, int16, int32 Unsigned integer uint8, uint16, uint32	boolean, single, double

Note that data type information can also be displayed in a model by selecting Port data types from the model window's Format menu.

• Sample mode

Checks whether the signal is discrete-time or continuous-time. (Note that when Sample time colors is selected from the Format menu, Simulink displays continuous-time signal lines in black or grey and discrete-time signal lines in colors corresponding to the relative rate. When a Probe block with Probe sample time enabled is attached to a continuous-time signal, the block icon displays the string Ts:[0 x], where x is the sample time offset. When a Probe block is attached to a discrete-time signal, the block icon displays the string Ts:[t 0] for a sample-based signal or Tf:[t 0] for a frame-based signal, where t is the nonzero sample period or frame period, respectively. Frame-based signals are almost always discrete-time.)

Dialog Box

Error if input

Specifies whether the block generates an error when the input possesses none of the required attributes (Does not match attributes exactly), or when the input possesses all of the required attributes (Matches attributes exactly).

Complexity

The complexity for which the input should be checked, Real or Complex.

Frame status

The frame status for which the input should be checked, Sample-based or Frame-based.

Dimensionality

Specifies whether the input should be checked for compliance (Is...) or noncompliance (Is not...) with the attributes in the subordinate Dimension menu.

Dimensions

The dimensions for which the input should be checked. This parameter is available when Is... or Is not... is selected in the Dimensionality menu.

Data type

Specifies whether the input should be checked for compliance (Is...) or noncompliance (Is not...) with the attributes in the subordinate General data type menu.

General data type

The general data type for which the input should be checked. This parameter is available when Is... or Is not... is selected in the Data type menu, and enables the subordinate Specific data type parameter in most cases.

Specific data type

The specific data type for which the input should be checked. This parameter is available when Floating-point, Fixed-point, or Integer is selected in the General data type menu.

Sample mode

The sample mode for which the input should be checked, Discrete or Continuous.

See Also

Buffer	DSP Blockset
Convert 1-D to 2-D	DSP Blockset
Convert 2-D to 1-D	DSP Blockset
Data Type Conversion	Simulink
Frame Status Conversion	DSP Blockset
Inherit Complexity	DSP Blockset
Probe	Simulink
Reshape	Simulink
Submatrix	DSP Blockset

Burg Method

Chirp