While Iterator
Repeat execution of a subsystem while a logical expression is true
- Library:
Ports & Subsystems
Description
The While Iterator block, when placed in a Subsystem
block, repeatedly executes the contents of the subsystem during the current time step
while the value of the input condition is true or 1. Use this block
to implement the block diagram equivalent of a while loop in a
programming language.
The While Iterator Subsystem block is preconfigured with a While Iterator block. Placing a While Iterator block in a Subsystem block makes it an atomic subsystem.
Ports
Input
Output Arguments
Parameters
Maximum number of iterations — Specify maximum number of iterations
-1 (default) | integer
Specify maximum number of iterations allowed during a time step.
-1Any number of iterations as long as the
condsignal is true (value not equal to0) . If you specify-1and thecondsignal never becomes false (0), the simulation runs in an infinite loop. In this case, the only way to stop the simulation is to terminate MATLAB®.- integer
Maximum number of iterations during a time step.
Programmatic Use
Block Parameter:
MaxIters |
| Type: character vector |
Values: '5'
| '-1' |
'<integer>' |
Default:
'5' |
While loop type — Select type of block
while (default) | do-while
Select type of block.
whileThe While Iterator block has two inputs, a
cond(logical condition) input and anIC(initial logical condition) input. The source of theICsignal must be external to the While Iterator Subsystem block.At the beginning of each time step:
If the
ICinput is true (value not equal to0), the blocks in the subsystem repeat execution while thecondinput is true. This process continues during a time step as long as thecondinput is true and the number of iterations is less than or equal to the Maximum number of iterations.If the
ICinput is false, the While Iterator block does not execute the contents of the subsystem.
do-whileThe While Iterator block has one input, the
cond(while condition) input.At each time step, the blocks in the subsystem repeat execution while the
condinput is true (value not equal to0). This process continues as long as thecondinput is true and the number of iterations is less than or equal to the Maximum number of iterations.
Programmatic Use
Block Parameter:
WhileBlockType |
| Type: character vector |
Values:
'while' |
'do-while' |
Default:
'while' |
States when starting — Select block states between time steps
held (default) | reset
Select how to handle block states between time steps.
heldHold block states between time steps. Block state values persist across time steps.
resetReset block states to their initial values at the beginning of each time step and before the first iteration loop.
Programmatic Use
Block Parameter:
ResetStates |
| Type: character vector |
Values:
'held' | 'reset' |
Default:
'held' |
Show iteration number port — Control display of output port
clear | select
Control display of output port for signal with number of block executions.
The value of the signal from this port starts at
11 for each succeeding iteration.
offRemove output port.
onDisplay output port for signal with iteration number.
Dependencies
Selecting this parameter enables the Output data type parameter.
Programmatic Use
Block Parameter:
ShowIterationPort |
| Type: character vector |
Values:
'off' | 'on' |
Default:
'off' |
Output data type — Select output data type for current iteration number
int32 (default) | uint32 | int16 | uint16 | int8 | uint8 | double
Select output data type for iteration number signal. The value of this signal is the number of iterations during a time step and the total number of iterations at the end of a time step.
int32Signed 32-bit integer.
uint32Unsigned 32-bit integer.
int16Signed 16-bit integer.
uint16unsigned 16-bit integer.
int8Signed 8-bit integer.
uint8Unsigned 8-bit integer.
doubleDouble-precision floating point.
Dependencies
Select the Show iteration number port check box to enable this parameter.
Programmatic Use
Block Parameter:
OutputDataType |
| Type: character vector |
Value:
'int32' |
'unt32'|'int16' |
'uint16'|'int8' |
'uint8'|'double' |
Default:
'int32' |
