Delay a signal one sample period.

Description

The FixPt Unit Delay block is a masked S-function that delays its input by the specified sample period. This block is equivalent to the z^-1 discrete-time operator. The block accepts one input and generates one output, both of which can be scalar or vector. If the input is a vector, all elements of the vector are delayed by the same sample period.

You specify the block output for the first sampling period with the Initial condition parameter. Careful selection of this parameter can minimize unwanted output behavior. The time between samples is specified with the Sample time parameter.

Remarks

This block provides a mechanism for discretizing one or more signals in time, or resampling the signal at a different rate. If your model contains multirate transitions, then you must add FixPt Unit Delay blocks between the slow to fast transitions. The sample rate of the FixPt Unit Delay must be set to that of the slower block.

For fast to slow transitions, use the FixPt Zero Order Hold block. For more information about multirate transitions, refer to Using Simulink or the Real-Time Workshop User's Guide.

Parameters and Dialog Box

• Initial condition - The initial output of the simulation.

• Sample time - Sample time.

Conversions

The Initial condition parameter is converted from a double to the input data type offline using round-to-nearest and saturation.

Characteristics