Discrete Variable Time Delay
Delays the signal for a variable time value.
Description
Block Discrete Variable Time Delay delays the input signal by the value specified at input D. At each simulation time step, the block Discrete Variable Time Delay stores the time and input value in an internal buffer and outputs the previous input value defined by the delay input.
If the delay input is not an integer of the time step, the block Discrete Variable Time Delay performs a linear interpolation. If the checkbox is selected Direct feedthrough, then the delay can be less than the simulation time step.
Ports
Input
#
In
—
input signal
scalar | vector | matrix 1 by N | matrix N by 1
Details
Input signal.
| Data types |
|
| Complex numbers support |
No |
#
D
—
signal delay
scalar | vector | matrix 1 by N | matrix N by 1
Details
Input delay signal.
| Data types |
|
| Complex numbers support |
No |
Output
#
Out
—
output signal
scalar | vector
Details
Delayed output signal.
| Data types |
|
| Complex numbers support |
No |
Parameters
Main
#
Maximum delay (s) —
expected maximum input delay D
Real number
Details
Specify the expected maximum input delay D.
Parameters Maximum delay (s) defines the size of the input buffer. If the input delay exceeds the specified maximum delay, it is trimmed to the allowable maximum value.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Initial conditions —
initial states
Scalar / array of real numbers
Details
Specify the initial state of the signal.
The unit outputs the specified values until the first delayed signal is output.
Set 0 to realise zero initial output, or specify the previous input values of the signal to start from the steady state.
The number of input values required is , where is the delay value at , and is the interval between calculation steps.
Suppose, for example, that the signal is a 60 Hz sine wave, the initial delay is set to by the D input of the block, and the interval between calculation steps is 50e-6 s. previous input values of the signal are defined as follows:
- ;
- time vector of previous inputs;
- previous input values of the signal.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Sample time —
interval between calculation steps
SampleTime (real number / vector of two real numbers)
Details
Specify the interval between calculation steps.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Direct feedthrough —
direct passage
Logical
Details
If this checkbox is selected, the block can operate with a delay shorter than the simulation time step. Otherwise, the block extrapolates the input values.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |