Enable - Add enable port to subsystem or model - Simulink (original) (raw)
Add enable port to subsystem or model
Libraries:
Simulink / Ports & Subsystems
HDL Coder / Ports & Subsystems
Description
The Enable block allows an external signal to control execution of a subsystem or a model. To enable this functionality, add the block to aSubsystem block or at the root level of a model that is referenced by aModel block.
If you use an enable port at the root-level of a model:
- For multi-rate models, set the solver to single-tasking.
- For models with a fixed-step size, at least one block in the model must run at the specified fixed-step size rate.
Examples
Ports
Output
Enable signal attached externally to the outside of an Enabled Subsystem block and passed to the inside of the subsystem. An enable signal port is added to an Enable block when you select the Show output port parameter.
Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean | fixed point | expression
Parameters
When a Subsystem block or Model block is disabled, select what happens to block states for the blocks within the subsystem or model.
held
Hold block states at their previous values.
reset
Reset block states to their initial conditions (zero if not defined).
Programmatic Use
| Block parameter: StatesWhenEnabling |
|---|
| Type: character vector |
| Values: 'held' | 'reset' |
| Default: 'held' |
Select when to propagate a variable-size signal.
Only when enabling
Propagate a variable-size signal when reenabling aSubsystem block or Model block containing an Enable port block. When you select this option, sample time must be periodic.
During execution
Propagate variable-size signals at each time step.
Programmatic Use
| Block parameter: PropagateVarSize |
|---|
| Type: character vector |
| Values: 'Only when enabling' | 'During execution' |
| Default: 'Only when enabling' |
The output port passes the enable signal attached externally to the outside of an Enabled Subsystem block or enabledModel block to the inside.
off
Remove the output port on the Enable port block.
on
Display an output port on the Enable port block. Selecting this option allows the subsystem or model to process the enable signal.
Programmatic Use
| Block parameter: ShowOutputPort |
|---|
| Type: character vector |
| Values: 'off' | 'on' |
| Default: 'off' |
Control zero-crossing detection for a model.
on
Detect zero crossings.
off
Do not detect zero crossings.
Programmatic Use
| Block parameter: ZeroCross |
|---|
| Type: character vector |
| Values: 'on' | 'off' |
| Default: 'on' |
Specify dimensions for the enable signal attached externally to aModel block and passed to the inside of the block.
1
Scalar signal.
[n]
Vector signal of width n.
[m n]
Matrix signal having m rows andn columns.
Programmatic Use
| Block parameter: PortDimensions | |
|---|---|
| Type: character vector | |
| Values: '1' | '[n]' | '[m n]' |
| Default: '1' |
Specify time interval between block method execution. See Specify Sample Time.
-1
Sample time inherited from the model.
Ts
Scalar where Ts is the time interval.
[Ts, To]
Vector where Ts is the time interval and To is the initial time offset.
Programmatic Use
| Block parameter: SampleTime | |
|---|---|
| Type: character vector | |
| Values: '-1' | 'Ts' | '[Ts, To]' |
| Default: '-1' |
Specify minimum value for the enable signal attached externally to aModel block and passed to the inside of the block.
Simulink® uses this value to perform:
- Simulation range checking. See Specify Signal Ranges.
- Automatic scaling of fixed-point data types.
- Optimization of generated code. This optimization can remove algorithmic code and affect the results of some simulation modes such as SIL or external mode. See Optimize using the specified minimum and maximum values (Embedded Coder).
[]
Unspecified minimum value.
real scalar
Real double scalar value.
Programmatic Use
| Block parameter: OutMin |
|---|
| Type: character vector |
| Values: '[]' | real scalar in quotes |
| Default: '[]' |
Specify maximum value for the enable signal attached externally to aModel block and passed to the inside of the block.
Simulink uses this value to perform:
- Simulation range checking. See Specify Signal Ranges.
- Automatic scaling of fixed-point data types.
- Optimization of generated code. This optimization can remove algorithmic code and affect the results of some simulation modes such as SIL or external mode. See Optimize using the specified minimum and maximum values (Embedded Coder).
[]
Unspecified maximum value.
real scalar
Real double scalar value.
Programmatic Use
| Block parameter: OutMax |
|---|
| Type: character vector |
| Values: '[]' | real scalar in quotes |
| Default: '[]' |
Specify data type for the enable signal attached externally to aModel block and passed to the inside of the block.
double
Double-precision floating point.
single
Single-precision floating point.
int8
Signed 8-bit integer.
uint8
Unsigned 8-bit integer.
int16
Signed 16-bit integer.
uint16
Unsigned 16-bit integer.
int32
Signed 32-bit integer.
uint32
Unsigned 32-bit integer.
int64
Signed 64-bit integer.
uint64
Unsigned 64-bit integer.
boolean
Boolean with a value of true orfalse.
fixdt(1,16)
Signed 16-bit fixed point number with binary point undefined.
fixdt(1,16,0)
Signed 16-bit fixed point number with binary point set to zero.
fixdt(1,16,2^,0)
Signed 16-bit fixed point number with slope set to2^0 and bias set to0.
<data type expression>
Data type object, for exampleSimulink.NumericType. You cannot enter the name of a Simulink.Bus object as a data type expression.
Programmatic Use
| Block parameter: OutDataTypeStr | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Type: character vector | |||||||||||||
| Values: 'double' | 'single' | 'int8' | 'uint8' | 'int16' | 'uint16' | 'int32' | 'uint32' | 'int64' | 'uint64' | 'boolean' | '<fixdt(1,16)' | 'fixdt(1,16,0)' | 'fixdt(1,16,2^0,0)' | '' |
| Default: 'double' |
Select data type category and display drop-down lists to help you define the data type.
Built in
Display drop-down lists for data type and Data type override.
Fixed point
Display drop-down lists for Signedness, Scaling, and Data type override.
Expression
Display box for entering an expression.
Dependency
To enable this parameter, select the Show data type assistant button.
Programmatic Use
No equivalent command-line parameter.
Specify value of missing workspace data when loading data from the workspace.
on
Linearly Interpolate output at time steps for which no corresponding workspace data exists.
off
Do not interpolate output at time steps. The current output equals the output at the most recent time step for which data exists.
Programmatic Use
| Block parameter: Interpolate |
|---|
| Type: character vector |
| Values: 'on' | 'off' |
| Default: 'on' |
Block Characteristics
| Data Types | Boolean | double | fixed point | integer | single |
|---|---|---|---|---|
| Direct Feedthrough | no | |||
| Multidimensional Signals | yes | |||
| Variable-Size Signals | no | |||
| Zero-Crossing Detection | yes |
Extended Capabilities
HDL Coder™ provides additional configuration options that affect HDL implementation and synthesized logic.
For more information, see HDL Code Generation in Enabled Subsystem.
HDL Architecture
This block has one default HDL architecture.
Version History
Introduced before R2006a