Tapped Delay

Delay scalar signal multiple sample periods and output all delayed versions




The Tapped Delay block delays an input by the specified number of sample periods and outputs all the delayed versions. Use this block to discretize a signal in time or resample a signal at a different rate.

The block accepts one scalar input and generates an output vector that contains each delay. Specify the order of the delays in the output vector with the Order output vector starting with parameter:

  • Oldest orders the output vector starting with the oldest delay version and ending with the newest delay version.

  • Newest orders the output vector starting with the newest delay version and ending with the oldest delay version.

Specify the output vector for the first sampling period with the Initial condition parameter. Careful selection of this parameter can minimize unwanted output behavior.

Specify the time between samples with the Sample time parameter. Specify the number of delays with the Number of delays parameter. A value of -1 instructs the block to inherit the number of delays by back propagation. Each delay is equivalent to the z-1 discrete-time operator, which the Unit Delay block represents.

Data Type Support

The Tapped Delay block accepts signals of the following data types:

  • Floating point

  • Built-in integer

  • Fixed point

  • Boolean

For more information, see Data Types Supported by Simulink in the Simulink® documentation.


Initial condition

Specify the initial output of the simulation. The Initial condition parameter is converted from a double to the input data type offline using round-to-nearest and saturation. Simulink software does not allow you to set the initial condition of this block to inf or NaN.

Sample time

Specify the time interval between samples. To inherit the sample time, set this parameter to -1. See Specify Sample Time in the online Simulink documentation for more information.

Number of delays

Specify the number of discrete-time operators.

Order output vector starting with

Specify whether to output the oldest delay version first, or the newest delay version first.

Include current input in output vector

Select to include the current input in the output vector.


Data Types

Double | Single | Boolean | Base Integer | Fixed-Point

Sample Time

Specified in the Sample time parameter

Direct Feedthrough

Yes, when Include current input in output vector check box is selected. No, otherwise.

Multidimensional Signals


Variable-Size Signals


Code Generation


Introduced before R2006a

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