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Discrete
You can use the Discrete-Time Integrator block in place of the Integrator block to create a purely discrete system. With the Discrete-Time Integrator block, you can:
Define initial conditions on the block dialog box or as input to the block.
Define an input gain (K) value.
Output the block state.
Define upper and lower limits on the integral.
Reset the state depending on an additional reset input.
The block can integrate or accumulate using the Forward Euler, Backward Euler, and Trapezoidal methods. Assume that u is the input, y is the output, and x is the state. For a given step n, Simulink updates y(n) and x(n+1). In integration mode, T is the block sample time (delta T in the case of triggered sample time). In accumulation mode, T = 1; the block sample time determines when the output is computed but not the output value. K is the gain value. Values clip according to upper or lower limits.
Forward Euler method (the default), also known as Forward Rectangular, or left-hand approximation.
For this method, 1/s is approximated by T/(z-1). The resulting expression for the output of the block at step n is:
y(n) = y(n-1) + K*T*u(n-1)
Let x(n+1) = x(n) + K*T*u(n). The block uses the following steps to compute its output:
Step 0: y(0) = x(0) = IC (clip if necessary) x(1) = y(0) + K*T*u(0) Step 1: y(1) = x(1) x(2) = x(1) + K*T*u(1) Step n: y(n) = x(n) x(n+1) = x(n) + K*T*u(n) (clip if necessary)
With this method, input port 1 does not have direct feedthrough.
Backward Euler method, also known as Backward Rectangular or right-hand approximation.
For this method, 1/s is approximated by T*z/(z-1). The resulting expression for the output of the block at step n is:
y(n) = y(n-1) + K*T*u(n)
Let x(n) = y(n-1). The block uses the following steps to compute its output
Step 0: y(0) = x(0) = IC (clipped if necessary) x(1) = y(0)
or, depending on Use initial condition as initial and reset value for parameter:
Step 0: x(0) = IC (clipped if necessary) x(1) = y(0) = x(0) + K*T*u(0) Step 1: y(1) = x(1) + K*T*u(1) x(2) = y(1) Step n: y(n) = x(n) + K*T*u(n) x(n+1) = y(n)
With this method, input port 1 has direct feedthrough.
Trapezoidal method. For this method, 1/s is approximated by
T/2*(z+1)/(z-1)
When T is fixed (equal to the sampling period), let
x(n) = y(n-1) + K*T/2 * u(n-1)
The block uses the following steps to compute its output
Step 0: x(0) = IC (clipped if necessary) x(1) = y(0) + K*T/2 * u(0)
or, depending on Use initial condition as initial and reset value for parameter:
Step 0: y(0) = x(0) = IC (clipped if necessary) x(1) = y(0) = x(0) + K*T/2*u(0) Step 1: y(1) = x(1) + K*T/2 * u(1) x(2) = y(1) + K*T/2 * u(1) Step n: y(n) = x(n) + K*T/2 * u(n) x(n+1) = y(n) + K*T/2 * u(n)
Here, x(n+1) is the best estimate of the next output. It is not the same as the state, in the sense that x(n) != y(n).
If T is variable (for example, obtained from the triggering times), the block uses the following algorithm to compute the outputs
Step 0: y(0) = x(0) = IC (clipped if necessary) x(1) = y(0)
or, depending on Use initial condition as initial and reset value for parameter:
Step 0: y(0) = x(0) = IC (clipped if necessary) x(1) = y(0) = x(0) + K*T/2*u(0) Step 1: y(1) = x(1) + T/2 * (u(1) + u(0)) x(2) = y(1) Step n: y(n) = x(n) + T/2 * (u(n) + u(n-1)) x(n+1) = y(n)
With this method, input port 1 has direct feedthrough.
You can define the initial conditions as a parameter on the block dialog box or input them from an external signal:
To define the initial conditions as a block parameter, specify the Initial condition source parameter as internal and enter the value in the Initial condition parameter field.
To provide the initial conditions from an external source, specify the Initial condition source parameter as external. An additional input port appears under the block input:
In two situations, you must use the state port instead of the output port:
When the output of the block is fed back into the block through the reset port or the initial condition port, causing an algebraic loop. For an example of this situation, see the sldemo_bounce_two_integrators model.
When you want to pass the state from one conditionally executed subsystem to another, which can cause timing problems. For an example of this situation, see the sldemo_clutch model.
You can work around these problems by passing the state through the state port rather than the output port. Simulink generates the state at a slightly different time from the output, which protects your model from these problems. You output the block state by selecting the Show state port check box.
By default, the state port appears on the top of the block:
To prevent the output from exceeding specifiable levels, select the Limit output check box and enter the limits in the appropriate parameter fields. Doing so causes the block to function as a limited integrator. When the output reaches the limits, the integral action is turned off to prevent integral wind up. During a simulation, you can change the limits but you cannot change whether the output is limited. The block determines output as follows:
| When the integral is... | The output is... |
|---|---|
| Less than or equal to the Lower saturation limit and the input is negative | Held at the Lower saturation limit |
| Between the Lower saturation limit and the Upper saturation limit | The integral |
| Greater than or equal to the Upper saturation limit and the input is positive | Held at the Upper saturation limit |
To generate a signal that indicates when the state is being limited, select the Show saturation port check box. A saturation port appears below the block output port:
The signal has one of three values:
1 indicates that the upper limit is being applied.
0 indicates that the integral is not limited.
-1 indicates that the lower limit is being applied.
The block can reset its state to the initial condition you specify, based on an external signal. To cause the block to reset its state, select one of the External reset parameter choices. A trigger port appears below the block input port to indicate the trigger type:
The reset port has direct feedthrough. If the block output feeds back into this port, either directly or through a series of blocks with direct feedthrough, an algebraic loop results. To resolve this loop, feed the output of the block state port into the reset port instead. To access the block state, select the Show state port check box.
The External reset parameter lets you determine the attribute of the reset signal that triggers the reset. The trigger options include:
rising
Resets the state when the reset signal has a rising edge. For example, the following figure shows the effect that a rising reset trigger has on backward Euler integration.
falling
Resets the state when the reset signal has a falling edge. For example, the following figure shows the effect that a falling reset trigger has on backward Euler integration.
either
Resets the state when the reset signal rises or falls. For example, the following figure shows the effect that an either reset trigger has on backward Euler integration.
level
Resets and holds the output to the initial condition while the reset signal is nonzero. For example, the following figure shows the effect that a level reset trigger has on backward Euler integration.
sampled level
Resets the output to the initial condition when the reset signal is nonzero. For example, the following figure shows the effect that a sampled level reset trigger has on backward Euler integration.
When you select all options, the icon looks like this:
If you use simplified initialization mode, the behavior of the Discrete-Time Integrator block differs from its behavior in classic initialization mode. The new initialization behavior is more robust, and provides more consistent behavior in these cases:
In algebraic loops
On enable and disable
When comparing results using triggered sample time against results using explicit sample time, where the block is triggered at the same rate as the explicit sample time
In addition, the simplified initialization behavior makes it easier to convert Continuous-Time Integrator blocks to Discrete-Time Integrator blocks, because the initial conditions have the same meaning for both blocks.
For more information on classic and simplified initialization modes, see Underspecified initialization detection.
When you use simplified initialization mode, the Initial condition parameter applies only to the integrator output.
In addition, the Use initial condition as initial and reset value for parameter is disabled. The block uses the initial condition as the initial and reset value for the output.
When you use simplified initialization mode, the block starts from first time step n = 0 with initial output y(0) = IC ( clipped if necessary).
For a given step n > 0 with simulation time t(n), Simulink updates output y(n) as follows:
Forward Euler Method:
y(n) = y(n-1) + K*[t(n)-t(n-1)]*u(n-1)
Backward Euler Method:
y(n) = y(n-1) + K*[t(n)-t(n-1)]*u(n)
Trapezoidal Method:
y(n) = y(n-1) + K*[t(n)-t(n-1)]*[u(n)+u(n-1)]/2
Simulink automatically selects a state-space realization of these input-output equations depending on the block sample time, which can be explicit or triggered. When using explicit sample time, t(n)-t(n-1) reduces to the sample time T for all n > 0.
When you use simplified initialization mode, the enable and disable behavior of the block is simplified as follows:
At disable time td:
y(td) = y(td-1)
At enable time te:
If parent subsystem resets on enable:
y(te) = IC
In all other cases (see below):
y(te) = y(td)
When using simplified initialization mode, you cannot place the Discrete-Time Integrator block in an Iterator Subsystem.
In simplified initialization mode, Iterator subsystems do not maintain elapsed time, so Simulink reports an error if any block needing elapsed time, such as the Discrete-Time Integrator, is placed inside an Iterator Subsystem block.
Suppose that you have a function-call subsystem that contains an enabled subsystem, which contains a Discrete-Time Integrator block. The following behavior applies.
| Integrator Method | Sample Time Type of Function-Call Trigger Port | Value of delta T When Function-Call Subsystem Executes for the First Time After Enabled | Reason for Behavior |
|---|---|---|---|
Forward Euler | Triggered | t — tstart | When the function-call subsystem executes for the first time, the integrator algorithm uses tstart as the previous simulation time. |
Backward Euler and Trapezoidal | Triggered | t — tprevious | When the function-call subsystem executes for the first time, the integrator algorithm uses tprevious as the previous simulation time. |
Forward Euler, Backward Euler, and Trapezoidal | Periodic | Sample time of the function-call generator | In periodic mode, the Discrete-Time Integrator block uses sample time of the function-call generator for delta T. |
The Discrete-Time Integrator block accepts real signals of the following data types:
Floating point
Built-in integer
Fixed point
For more information, see Data Types Supported by Simulink in the Simulink documentation.
The Main pane of the Discrete-Time Integrator block dialog box appears as follows:
The Signal Attributes pane of the Discrete-Time Integrator block dialog box appears as follows:
The State Attributes pane of the Discrete-Time Integrator block dialog box appears as follows:
During simulation, the block uses the following values:
The initial value of the signal object to which the state name is resolved
Min and Max values of the signal object
For more information, see States in the Simulink Coder documentation.
Display the Data Type Assistant.
The Data Type Assistant helps you set the Output data type parameter.
See Specifying Block Output Data Types for more information.
See Block-Specific Parameters for the command-line information.
Specify the integration or accumulation method.
Default: Integration: Forward Euler
Integrator method is Forward Euler.
Integrator method is Backward Euler.
Integrator method is Trapezoidal.
Accumulation method is Forward Euler.
Accumulation method is Backward Euler.
Accumulation method is Trapezoidal.
See Block-Specific Parameters for the command-line information.
Specify a scalar, vector, or matrix by which to multiply the integrator input. Each element of the gain must be a positive real number.
Default: 1.0
Specifying a value other than 1.0 (the default) is semantically equivalent to connecting a Gain block to the input of the integrator.
Valid entries include:
double(1.0)
single(1.0)
[1.1 2.2 3.3 4.4]
[1.1 2.2; 3.3 4.4]
Using this parameter to specify the input gain eliminates a multiplication operation in the generated code. Realizing this benefit, however, requires that this parameter be nontunable. Accordingly, the Simulink Coder software generates a warning during code generation if the Model Parameter Configuration dialog box for this model declares this parameter to be tunable. If you want to tune the input gain, set this parameter to 1.0 and use an external Gain block to specify the input gain.
See Block-Specific Parameters for the command-line information.
Reset the states to their initial conditions when a trigger event occurs in the reset signal.
Default: none
Do not reset the state to initial conditions.
Reset the state when the reset signal has a rising edge.
Reset the state when the reset signal has a falling edge.
Reset the state when the reset signal rises or falls.
Reset and holds the output to the initial condition while the reset signal is nonzero.
Reset the output to the initial condition when the reset signal is nonzero.
See Block-Specific Parameters for the command-line information.
Get the initial conditions of the states.
Default: internal
Get the initial conditions of the states from the Initial condition parameter.
Get the initial conditions of the states from an external block.
Simulink software does not allow the initial condition of this block to be inf or NaN.
Selecting internal enables the Initial condition parameter.
Selecting external disables the Initial condition parameter.
See Block-Specific Parameters for the command-line information.
Specify the states' initial conditions.
Default: 0
Minimum: value of Output minimum parameter
Maximum: value of Output maximum parameter
Simulink software does not allow the initial condition of this block to be inf or NaN.
Setting Initial condition source to internal enables this parameter.
Setting Initial condition source to external disables this parameter.
See Block-Specific Parameters for the command-line information.
Specify whether to apply the initial condition as the initial and reset value for the state and output, or the state only.
Note If you are using simplified initialization mode, this parameter is disabled. The initial condition is always used as the initial and reset value for the output. For more information, see Underspecified initialization detection. |
Default: State and output
Set the following for initial
y(0) = IC
x(0) = IC
or at reset
y(n) = IC
x(n) = IC
Set the following for initial
x(0) = IC
or at reset
x(n) = IC
See Block-Specific Parameters for the command-line information.
Enter the discrete interval between sample time hits.
Default: 1
By default, the block uses a discrete sample time of 1. To set a different sample time, enter another discrete value, such as 0.1.
See also How to Specify the Sample Time in the online documentation for more information.
Do not specify a sample time of 0. This value specifies a continuous sample time, which the Discrete-Time Integrator block does not support.
Do not specify a sample time of inf or NaN because these values are not discrete.
If you specify -1 to inherit the sample time from an upstream block, verify that the upstream block uses a discrete sample time. For example, the Discrete-Time Integrator block cannot inherit a sample time of 0.
See Block-Specific Parameters for the command-line information.
Limit the block's output to a value between the Lower saturation limit and Upper saturation limit parameters.
Default: Off
On Limit the block's output to a value between the Lower saturation limit and Upper saturation limit parameters.
OffDo not limit the block's output to a value between the Lower saturation limit and Upper saturation limit parameters.
This parameter enables Upper saturation limit.
This parameter enables Lower saturation limit.
See Block-Specific Parameters for the command-line information.
Specify the upper limit for the integral.
Default: inf
Minimum: value of Output minimum parameter
Maximum: value of Output maximum parameter
Limit output enables this parameter.
See Block-Specific Parameters for the command-line information.
Specify the lower limit for the integral.
Default: -inf
Minimum: value of Output minimum parameter
Maximum: value of Output maximum parameter
Limit output enables this parameter.
See Block-Specific Parameters for the command-line information.
Add a saturation output port to the block.
Default: Off
See Block-Specific Parameters for the command-line information.
Add an output port to the block for the block's state.
Default: Off
On Add an output port to the block for the block's state.
OffDo not add an output port to the block for the block's state.
See Block-Specific Parameters for the command-line information.
Cause Simulink linearization commands to treat this block as not resettable and as having no limits on its output, regardless of the settings of the block reset and output limitation options.
Default: Off
On Cause Simulink linearization commands to treat this block as not resettable and as having no limits on its output, regardless of the settings of the block reset and output limitation options.
OffDo not cause Simulink linearization commands to treat this block as not resettable and as having no limits on its output, regardless of the settings of the block reset and output limitation options.
Ignoring the limit and resetting allows you to linearize a model around an operating point. This point may cause the integrator to reset or saturate.
See Block-Specific Parameters for the command-line information.
Select to lock the output data type setting of this block against changes by the Fixed-Point Tool and the Fixed-Point Advisor.
Default: Off
OnLocks the output data type setting for this block.
OffAllows the Fixed-Point Tool and the Fixed-Point Advisor to change the output data type setting for this block.
See Block-Specific Parameters for the command-line information.
For more information, see Fixed-Point Tool and Fixed-Point Advisor in the Simulink Fixed Point documentation.
Specify the rounding mode for fixed-point operations.
Default: Floor
Rounds both positive and negative numbers toward positive infinity. Equivalent to the MATLAB ceil function.
Rounds number to the nearest representable value. If a tie occurs, rounds to the nearest even integer. Equivalent to the Fixed-Point Toolbox convergent function.
Rounds both positive and negative numbers toward negative infinity. Equivalent to the MATLAB floor function.
Rounds number to the nearest representable value. If a tie occurs, rounds toward positive infinity. Equivalent to the Fixed-Point Toolbox nearest function.
Rounds number to the nearest representable value. If a tie occurs, rounds positive numbers toward positive infinity and rounds negative numbers toward negative infinity. Equivalent to the Fixed-Point Toolbox round function.
Automatically chooses between round toward floor and round toward zero to generate rounding code that is as efficient as possible.
Rounds number toward zero. Equivalent to the MATLAB fix function.
See Block-Specific Parameters for the command-line information.
For more information, see Rounding in the Simulink Fixed Point User's Guide.
Specify whether overflows saturate.
Default: Off
OnOverflows saturate to either the minimum or maximum value that the data type can represent.
For example, an overflow associated with a signed 8-bit integer can saturate to -128 or 127.
OffOverflows wrap to the appropriate value that is representable by the data type.
For example, the number 130 does not fit in a signed 8-bit integer and wraps to -126.
Consider selecting this check box when your model has possible overflow and you want explicit saturation protection in the generated code.
Consider clearing this check box when you want to optimize efficiency of your generated code.
Clearing this check box also helps you avoid overspecifying how a block handles out-of-range signals. For more information, see Checking for Signal Range Errors.
When you select this check box, saturation applies to every internal operation on the block, not just the output or result.
In general, the code generation process can detect when overflow is not possible. In this case, the code generator does not produce saturation code.
See Block-Specific Parameters for the command-line information.
Use this parameter to assign a unique name to each state.
Default: ' '
If left blank, no name is assigned.
A valid identifier starts with an alphabetic or underscore character, followed by alphanumeric or underscore characters.
The state name applies only to the selected block.
This parameter enables State name must resolve to Simulink signal object when you click the Apply button.
For more information, see States in the Simulink Coder documentation.
See Block-Specific Parameters for the command-line information.
Require that state name resolve to Simulink signal object.
Default: Off
On Require that state name resolve to Simulink signal object.
OffDo not require that state name resolve to Simulink signal object.
State name enables this parameter.
Selecting this check box disables Code generation storage class.
See Block-Specific Parameters for the command-line information.
Select a package that defines the custom storage class you want to apply.
Default: ---None---
Sets internal storage class attributes.
Applies the built-in mpt package.
Applies the built-in Simulink package.
If you have defined any packages of your own, click Refresh. This action adds all user-defined packages on your search path to the package list.
See Block-Specific Parameters for the command-line information.
Select state storage class.
Default: Auto
Auto is the appropriate storage class for states that you do not need to interface to external code.
State is stored in a global variable
model_private.h declares the state as an extern variable.
model_private.h declares the state as an extern pointer.
State name enables this parameter.
Setting this parameter to ExportedGlobal, ImportedExtern, or ImportedExternPointer enables Code generation storage type qualifier.
See Block-Specific Parameters for the command-line information.
Select custom storage class for state.
Default: Auto
Auto is the appropriate storage class for states that you do not need to interface to external code.
model_P initializes the state to its corresponding value in the workspace.
State is stored in a global variable
model_private.h declares the state as an extern variable.
model_private.h declares the state as an extern pointer.
A non-editable placeholder storage class is created.
A struct declaration is created that embeds Boolean data.
Volatile type qualifier is used in state declaration.
Header (.h) file containing global variable declarations is generated with user-specified name.
Predefined header (.h) files containing global variable declarations are included.
A static qualifier is generated in front of the state declaration to make the state visible only to the current file.
A struct declaration is created to encapsulate parameter or signal object data.
Volatile type qualifier is used in struct declaration.
Supports specialized function calls to read and write memory.
State name enables this parameter.
The list of valid storage classes differs based on the Package selection.
Setting this parameter to ExportedGlobal, ImportedExtern, or ImportedExternPointer enables Code generation storage type qualifier.
See Block-Specific Parameters for the command-line information.
Specify the Simulink Coder storage type qualifier.
Default: ' '
If left blank, no qualifier is assigned.
Setting Code generation storage class to ExportedGlobal, ImportedExtern, or ImportedExternPointer enables this parameter.
See Block-Specific Parameters for the command-line information.
Specify the minimum value that the block should output.
Default: [] (unspecified)
This number must be a finite real double scalar value.
Note If you specify a bus object as the data type for this block, do not set the minimum value for bus data on the block. Simulink ignores this setting. Instead, set the minimum values for bus elements of the bus object specified as the data type. For information on the Minimum property of a bus element, see Simulink.BusElement. |
Simulink uses the minimum to perform:
Parameter range checking (see Checking Parameter Values) for some blocks
Simulation range checking (see Signal Ranges)
Automatic scaling of fixed-point data types
See Block-Specific Parameters for the command-line information.
Specify the maximum value that the block should output.
Default: [] (unspecified)
This number must be a finite real double scalar value.
Note If you specify a bus object as the data type for this block, do not set the maximum value for bus data on the block. Simulink ignores this setting. Instead, set the maximum values for bus elements of the bus object specified as the data type. For information on the Maximum property of a bus element, see Simulink.BusElement. |
Simulink uses the maximum value to perform:
Parameter range checking (see Checking Parameter Values) for some blocks
Simulation range checking (see Signal Ranges)
Automatic scaling of fixed-point data types
See Block-Specific Parameters for the command-line information.
Specify the output data type.
Default: Inherit: Inherit via internal rule
Simulink chooses a combination of output scaling and data type that requires the smallest amount of memory consistent with accommodating the calculated output range and maintaining the output precision of the block and with the word size of the targeted hardware implementation specified for the model. If the Device type parameter on the Hardware Implementation configuration parameters pane is set to ASIC/FPGA, Simulink software chooses the output data type without regard to hardware constraints. Otherwise, Simulink software chooses the smallest available hardware data type capable of meeting the range and precision constraints. For example, if the block multiplies an input of type int8 by a gain of int16 and ASIC/FPGA is specified as the targeted hardware type, the output data type is sfix24. If Unspecified (assume 32-bit Generic), i.e., a generic 32-bit microprocessor, is specified as the target hardware, the output data type is int32. If none of the word lengths provided by the target microprocessor can accommodate the output range, Simulink software displays an error message in the Simulation Diagnostics Viewer.
Use data type of the driving block.
Output data type is double.
Output data type is single.
Output data type is int8.
Output data type is uint8.
Output data type is int16.
Output data type is uint16.
Output data type is int32.
Output data type is uint32.
Output data type is fixed point fixdt(1,16,0).
Output data type is fixed point fixdt(1,16,2^0,0).
Use a data type object, for example, Simulink.NumericType.
See Block-Specific Parameters for the command-line information.
See Specifying Block Output Data Types in the Simulink User's Guide for more information.
Select the category of data to specify.
Default: Inherit
Inheritance rules for data types. Selecting Inherit enables a second menu/text box to the right. Select one of the following choices:
Inherit via internal rule (default)
Inherit via back propagation
Built-in data types. Selecting Built in enables a second menu/text box to the right. Select one of the following choices:
double (default)
single
int8
uint8
int16
uint16
int32
uint32
Fixed-point data types.
Expressions that evaluate to data types. Selecting Expression enables a second menu/text box to the right, where you can enter the expression.
Clicking the Show data type assistant button enables this parameter.
See Block-Specific Parameters for the command-line information.
See Using the Data Type Assistant in the Simulink User's Guide.
Specify data type override mode for this signal.
Default: Inherit
Inherits the data type override setting from its context, that is, from the block, Simulink.Signal object or Stateflow chart in Simulink that is using the signal.
Ignores the data type override setting of its context and uses the fixed-point data type specified for the signal.
The ability to turn off data type override for an individual data type provides greater control over the data types in your model when you apply data type override. For example, you can use this option to ensure that data types meet the requirements of downstream blocks regardless of the data type override setting.
This parameter appears only when the Mode is Built in or Fixed point.
Specify whether you want the fixed-point data as signed or unsigned.
Default: Signed
Selecting Mode > Fixed point enables this parameter.
See Block-Specific Parameters for the command-line information.
See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.
Specify the bit size of the word that holds the quantized integer.
Default: 16
Minimum: 0
Maximum: 32
Selecting Mode > Fixed point enables this parameter.
See Block-Specific Parameters for the command-line information.
See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.
Specify the method for scaling your fixed-point data to avoid overflow conditions and minimize quantization errors.
Default: Best precision
Specify binary point location.
Enter slope and bias.
Specify best-precision values.
Selecting Mode > Fixed point enables this parameter.
Selecting Binary point enables:
Fraction length
Calculate Best-Precision Scaling
Selecting Slope and bias enables:
Slope
Bias
Calculate Best-Precision Scaling
See Block-Specific Parameters for the command-line information.
See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.
Specify fraction length for fixed-point data type.
Default: 0
Binary points can be positive or negative integers.
Selecting Scaling > Binary point enables this parameter.
See Block-Specific Parameters for the command-line information.
See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.
Specify slope for the fixed-point data type.
Default: 2^0
Specify any positive real number.
Selecting Scaling > Slope and bias enables this parameter.
See Block-Specific Parameters for the command-line information.
See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.
Specify bias for the fixed-point data type.
Default: 0
Specify any real number.
Selecting Scaling > Slope and bias enables this parameter.
See Block-Specific Parameters for the command-line information.
See Specifying a Fixed-Point Data Type in the Simulink User's Guide for more information.
The sldemo_fuelsys model uses a Discrete-Time Integrator block in the fuel_rate_control/airflow_calc subsystem. This block uses the Forward Euler integration method.
When the Switch block feeds a nonzero value into the Discrete-Time Integrator block, integration occurs. Otherwise, integration does not occur.
For more information, see the model description.
Direct Feedthrough | Yes, of the reset and external initial condition source ports. The input has direct feedthrough for every integration method except Forward Euler and accumulation Forward Euler. |
Sample Time | Specified in the Sample time parameter |
Scalar Expansion | Yes, of parameters |
States | Inherited from driving block and parameter |
Dimensionalized | Yes |
Multidimensionalized | No |
Zero-Crossing Detection | No |
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