Main Content

Dead Zone

Provide region of zero output

  • Dead Zone block

Libraries:
Simulink / Discontinuities
HDL Coder / Discontinuities

Description

The Dead Zone block generates zero output within a specified region, called its dead zone. You specify the lower limit (LL) and upper limit (UL) of the dead zone as the Start of dead zone and End of dead zone parameters. The block output depends on the input (U) and the values for the lower and upper limits.

InputOutput
U >= LL and U <= ULZero
U > ULUUL
U < LLULL

Examples

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This example shows the effect of the Dead Zone block on a sine wave. The model uses a dead zone lower limit of -0.5 and an upper limit of 0.5. Set these values using the parameters Start of Dead Zone and End of Dead Zone.

Ports

Input

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Input signal to the dead-zone algorithm.

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

Output

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Output signal after the dead-zone algorithm is applied to the input signal.

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

Parameters

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Specify dead zone lower limit. Set the value for Start of dead zone less than or equal to End of dead zone. When the input value is less than Start of dead zone, then the block shifts the output value down by the Start of dead zone value.

Programmatic Use

Block Parameter: LowerValue
Type: character vector
Value: scalar or vector less than or equal to UpperValue.
Default: '-0.5'

Specify dead zone upper limit. Set the value for End of dead zone greater than or equal to Start of dead zone. When the input value is greater than End of dead zone, then the block shifts the output value down by the End of dead zone value.

Programmatic Use

Block Parameter: UpperValue
Type: character vector
Value: scalar or vector greater than or equal to LowerValue.
Default: '0.5'

Specify whether overflows saturate or wrap.

  • on — Overflows saturate to either the minimum or maximum value that the data type can represent.

  • off — Overflows wrap to the appropriate value that the data type can represent.

For example, the maximum value that the signed 8-bit integer int8 can represent is 127. Any block operation result greater than this maximum value causes overflow of the 8-bit integer.

  • With this parameter selected, the block output saturates at 127. Similarly, the block output saturates at a minimum output value of -128.

  • With this parameter cleared, the software interprets the overflow-causing value as int8, which can produce an unintended result. For example, a block result of 130 (binary 1000 0010) expressed as int8 is -126.

Tips

  • Consider selecting this parameter when your model has a possible overflow and you want explicit saturation protection in the generated code.

  • Consider clearing this parameter when you want to optimize efficiency of your generated code. Clearing this parameter also helps you to avoid overspecifying how a block handles out-of-range signals. For more information, see Troubleshoot Signal Range Errors.

  • When you select this parameter, saturation applies to every internal operation on the block, not just the output or result.

  • In general, the code generation process can detect when overflow is not possible. In this case, the code generator does not produce saturation code.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

Parameter: SaturateOnIntegerOverflow
Values: 'on' (default) | 'off'

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

Programmatic Use

Block Parameter: LinearizeAsGain
Type: character vector
Value: '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

To set the block parameter value programmatically, use the set_param function.

Parameter: SampleTime
Values: "-1" (default) | scalar or vector in quotes

Block Characteristics

Data Types

double | fixed point | integer | single

Direct Feedthrough

yes

Multidimensional Signals

no

Variable-Size Signals

no

Zero-Crossing Detection

yes

More About

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Extended Capabilities

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

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

Version History

Introduced before R2006a