Main Content

Saturation

Limit input signal to the upper and lower saturation values

  • Saturation block

Libraries:
Simulink / Commonly Used Blocks
Simulink / Discontinuities
HDL Coder / Discontinuities

Description

The Saturation block produces an output signal that is the value of the input signal bounded to the upper and lower saturation values. The upper and lower limits are specified by the parameters Upper limit and Lower limit.

InputOutput
Lower limit ≤ Input value ≤ Upper limitInput value
Input value < Lower limitLower limit
Input value > Upper limitUpper limit

Ports

Input

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The input signal to the saturation algorithm.

Data Types: double | single | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | fixed point

Output

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Output signal that is the value of the input signal, upper saturation limit, or lower saturation limit.

Data Types: double | single | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | fixed point

Parameters

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Main

Specify the upper bound on the input signal. If the input signal is greater than this boundary, then the output signal is set to this saturation value. The Upper limit parameter is converted to the output data type using round-to-nearest and saturation. Upper limit must be greater than the Output minimum parameter and less than the Output maximum parameter.

Programmatic Use

Block Parameter: UpperLimit
Type: character vector
Value: real scalar or vector
Default: '0.5'

Specify the lower bound on the input signal. If the input signal is less than this boundary, then the output signal is set to this saturation value. The Lower limit parameter is converted to the output data type using round-to-nearest and saturation. Lower limit must be greater than the Output minimum parameter and less than the Output maximum parameter.

Programmatic Use

Block Parameter: LowerLimit
Type: character vector
Value: real scalar or vector
Default: '-0.5'

Select this check box to cause the commands to treat the gain as 1. The linearization commands in Simulink® software treat this block as a gain in state space. Clear the box to have the commands treat the gain as 0.

Programmatic Use

Block Parameter: LinearizeAsGain
Type: character vector
Values: 'off' | 'on'
Default: 'on'

Select to enable zero-crossing detection. For more information, see Zero-Crossing Detection.

Programmatic Use

Block Parameter: ZeroCross
Type: character vector | string
Values: 'off' | 'on'
Default: 'on'

Specify the time interval between samples. To inherit the sample time, set this parameter to -1. For more information, see Specify Sample Time.

Dependencies

This parameter is visible only if you set it to a value other than -1. To learn more, see Blocks for Which Sample Time Is Not Recommended.

Programmatic Use

Block Parameter: SampleTime
Type: string scalar or character vector
Default: "-1"

Signal Attributes

The Data Type Assistant helps you set data attributes. To use the Data Type Assistant, click the Show data type assistant button. For more information, see Specify Data Types Using Data Type Assistant.

Lower value of the output range that Simulink checks.

Simulink uses the minimum to perform:

Note

Output minimum does not saturate or clip the actual output signal. Use the Saturation block instead.

Programmatic Use

Block Parameter: OutMin
Type: character vector
Values: '[ ]'| scalar
Default: '[ ]'

Upper value of the output range that Simulink checks.

Simulink uses the maximum value to perform:

Note

Output maximum does not saturate or clip the actual output signal. Use the Saturation block instead.

Programmatic Use

Block Parameter: OutMax
Type: character vector
Values: '[ ]'| scalar
Default: '[ ]'

Choose the data type for the output. The type can be inherited, specified directly, or expressed as a data type object such as Simulink.NumericType. For more information, see Control Data Types of Signals.

Programmatic Use

Block Parameter: OutDataTypeStr
Type: character vector
Values: 'Inherit: Same as input', 'Inherit: Inherit via back propagation', 'single', 'int8', 'uint8', int16, 'uint16', 'int32', 'uint32', 'int64', 'uint64', fixdt(1,16,0), fixdt(1,16,2^0,0), fixdt(1,16,2^0,0). '<data type expression>'
Default: 'Inherit: Same as input'

Select this parameter to prevent the fixed-point tools from overriding the Output data type you specify on the block. For more information, see Use Lock Output Data Type Setting (Fixed-Point Designer).

Programmatic Use

Block Parameter: LockScale
Type: character vector
Values: 'off' | 'on'
Default: 'off'

Choose one of these rounding modes.

Ceiling

Rounds both positive and negative numbers toward positive infinity. Equivalent to the MATLAB® ceil function.

Convergent

Rounds number to the nearest representable value. If a tie occurs, rounds to the nearest even integer. Equivalent to the Fixed-Point Designer™ convergent function.

Floor

Rounds both positive and negative numbers toward negative infinity. Equivalent to the MATLAB floor function.

Nearest

Rounds number to the nearest representable value. If a tie occurs, rounds toward positive infinity. Equivalent to the Fixed-Point Designer nearest function.

Round

Rounds number to the nearest representable value. If a tie occurs, rounds positive numbers toward positive infinity and rounds negative numbers toward negative infinity. Equivalent to the Fixed-Point Designer round function.

Simplest

Automatically chooses between round toward floor and round toward zero to generate rounding code that is as efficient as possible.

Zero

Rounds number toward zero. Equivalent to the MATLAB fix function.

Programmatic Use

Block Parameter: RndMeth
Type: character vector
Values: 'Ceiling' | 'Convergent' | 'Floor' | 'Nearest' | 'Round' | 'Simplest' | 'Zero'
Default: 'Floor'

See Also

For more information, see Rounding (Fixed-Point Designer).

Block Characteristics

Data Types

double | fixed point | integer | single

Direct Feedthrough

yes

Multidimensional Signals

no

Variable-Size Signals

no

Zero-Crossing Detection

yes

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

PLC Code Generation
Generate Structured Text code using Simulink® PLC Coder™.

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Version History

Introduced before R2006a