Unit Delay With Preview Enabled (Simulink Reference)

Simulink Reference

Unit Delay With Preview Enabled

Output the signal and the signal delayed by one sample period, if the external enable signal is on

Library

Additional Math & Discrete / Additional Discrete

Description

The Unit Delay With Preview Enabled block supports calculations that have feedback and depend on the current input.

The block has two output ports. When the external enable signal E is on, the upper port outputs the signal and the lower port outputs the signal delayed by one sample period. The block has two input ports, one for the input signal u and the other for the enable signal E.

When the enable signal E is off, the block is disabled, and the state and output values do not change, except for resets. The enable signal is on when E is not 0, and off when E is 0.

The input u and initial condition IC must be the same data type, but can be any data type. The output is the same data type as the inputs u and IC. The reset R can be any data type.

You specify the time between samples with the Sample time parameter. A setting of -1 means the Sample time is inherited.

Data Type Support

The Unit Delay With Preview Enabled block accepts signals of any data type supported by Simulink, including fixed-point data types.

Parameters and Dialog Box

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

Characteristics

Direct Feedthrough
Yes, to upper output port
No, to lower output port

Sample Time
Specified in the Sample time parameter

Scalar Expansion
Yes

Direct Feedthrough	Yes, to upper output port No, to lower output port
Sample Time	Specified in the Sample time parameter
Scalar Expansion	Yes

Unit Delay Resettable External IC Unit Delay With Preview Enabled Resettable