Simulink^®

Unit Delay With Preview Enabled Resettable External RV - Output signal and signal delayed by one sample period, if external enable signal is on, with external RV reset

Library

Additional Math & Discrete / Additional Discrete

Description

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

The block can reset its state based on an external reset signal R. The block has two output ports. When the external enable signal E is on and the reset R is false, the upper port outputs the signal and the lower port outputs the signal delayed by one sample period. The block has four input ports, one for the input signal u, one for the enable signal E, one for the reset signal R, and one for the external reset signal, RV.

When the enable signal E is on and the reset R is true, the upper output signal is forced to equal the external reset signal RV. The lower output signal is not affected until one time step later, at which time it is equal to the external reset signal RV at the previous time step. The block uses the internal Initial condition only when the model starts or when a parent enabled subsystem is used. The internal Initial condition only affects the lower output signal. The first output is only affected through feedback.

When the Enable signal 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 can be any data type. The output is the same data type as the input u. 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 Resettable External RV block accepts signals of any data type supported by Simulink software, including fixed-point and enumerated 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