Mathworks REAL-TIME WINDOWS TARGET 3 Reference

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Real-Time Windows

User’s Guide

Target™ 3

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Real-Time Windows Target™ User’s Guide

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Revision History

January 1999 First printing New for Version 1.0 (Release 11.0) January 2000 Second printing Revised for Version 1.5 (Release 11.1+) September 2000 Third printing Revised for Version 2.0 (Release R12) June 2001 Online only Revised for Version 2.1 (Release R12.1) July 2002 Online only Revised for Version 2.2 (Release 13) June 2004 Fourth printing Revised for Version 2.5 (Release 14) October 2004 Fifth printing Revised for Version 2.5.1 (Release 14SP1) March 2005 Online only Revised for Version 2.5.2 (Release 14SP2) September 2005 Online only Revised for Version 2.6 (Release 14SP3) March 2006 Online only Revised for Version 2.6.1 (Release 2006a) September 2006 Online only Revised for Version 2.6.2 (Release 2006b) March 2007 Online only Revised for Version 2.7 (Release 2007a) September 2007 Online only Revised for Version 3.0 (Release 2007b) March 2008 Online only Revised for Version 3.1 (Release 2008a) October 2008 Online only Revised for Version 3.2 (Release 2008b) March 2009 Online only Revised for Version 3.3 (Release 2009a) September 2009 Online only Revised for Version 3.4 (Release 2009b) March 2010 Online only Revised for Version 3.5 (Release 2010a)

Getting Started

Product Overview ................................. 1-2

Contents

Using This Guide

Features

Real-Time Kernel Real-Time Application Signal Acquisition and Analysis Parameter Tuning

Hardware Environment

PC-Compatible Computer Input/Output Driver Support

Software Environment

Non-Real-Time Simulation Real-Time Execution Development Process

System Concepts

Simulink External Mode Data Buffers and Transferring Data

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Installation and Configuration

Required Products ................................. 2-2

Platform The MATLAB Environment Simulink Software

......................................... 2-2

......................... 2-2

................................ 2-2

Real-Time W orkshop Code Generation Software ........ 2-3

Related Products

System Requirements

Platform Requirements Hardware Requirements Software Requirements

Real-Time Windows Target Installed Files

Initial Working Directory

Working Directory Location Requirement Setting the Working Directory from the Desktop Icon Setting the Working Directory from the MATLAB

Environment

Real-Time Windows Target Kernel

About the Kernel Installing the Kernel Uninstalling the Kernel

Testing the Installation

About Installation Testing Running the Model rtvdp.mdl Displaying S ta tus Information Detecting Excessive Sample Rates Demo Library

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vi Contents

Basic Procedures

Using Simulink Models ............................. 3-2

About Simulink Models Creating a Model Configuring a Model Running a Simulation

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Using Real-Time Applications ...................... 3-14

About Real-Time Applications Entering Simulation Parameters Entering Scope Parameters for Signal Tracing Creating a Real-Time Application Entering Additional Scope Parameters for Signal

Tracing Running a Real-Time A pplication Running an Application from the Command Line

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Logging Signals to the Base Workspace

About Signal Logging Entering Scope Parameters Entering Signal and Triggering Properties Plotting Logged Signal Data

Logging Signals to a Disk Drive

About Signal Logging Entering Scope Parameters Entering Signal and Triggering Properties Entering Data Archiving Parameters Plotting Logged Signal Data

Tuning Param eters

About Parameter Tuning Changing Model Parameters

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Boards, Blocks, and Drivers

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Introduction ...................................... 4-2

Using I/O Boards

About I/O Boards Installing and Configuring I/O Boards and Drivers ISA Bus Board PCI Bus Board PC/104 Board Compact PCI Board

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vii

PCMCIA Board ................................... 4-9

Using I/O Driver Blocks

About I/O Driver Blocks The Real-Time Windows Target Library Output Signals from an I/O Block Variations with Channel Selection

UsingAnalogI/ODrivers

About Analog Drivers I/O Driver Characteristics Normalized Scaling for Analog Inputs

Using Vector CAN Drivers

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Troubleshooting

Introduction ...................................... 5-2

Building Older Models

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viii Contents

Plots Not Visible in Simulink Scope Block

Failure to Connect to Target

Scope Output Delayed or Missing

S-Functions U sing Math F unctions

........................ 5-5

................... 5-6

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........... 5-4

Custom I/O Driver Blocks

Introduction ...................................... A-2

I/O Register Ac

Incompatibil

Unsupported

Supported C F

Simulin

Real-T

Signa

cess from S-Functions Limitation

ity with Win32 API Calls

C Functions

unctions

k Model Examples

ime Application Examples

l Logging to MATLAB Workspace Examples

l Logging to Disk Drive Examples

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A-3

A-4

A-5

A-6

Examples

B-2

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B-2

meter Tuning Examples

Para

Board Examples

I/O

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B-3

dex

x Contents

Getting Started

• “Product Overview” on page 1-2

• “Using This Guide” on page 1-4

• “Features” on page 1-5

• “Hardware Environment” on page 1-10

• “Software Environment” on p age 1-12

• “System Concepts” on page 1-15

1 Getting Started

Product Overview

Real-Time Windows Targe t™ rapid prototyping software is a PC solution for prototyping and testing real-time systems. Real-Time Windows Target software uses a single computer as a host and target. On this computer, you use the MATLAB (optional) to create models using Simulink blocks and Stateflow diagrams.

environment, Simulink®software, and Stateflow®software

After creating a model and simulating it using Simulink software in normal mode, you can generate executable code with Real-Time Workshop generation software, Stateflow and the Open Watcom C/C++ compiler. Thenyoucanrunyourapplicationin real time with Simulink external mode.

Integration betwe en Simulink external mode and Real-Time Windows Target software allows you to use your Simulink model as a graphical user i nterface for

• Signal visualization — Use the same Simulink Scope blocks that you use

to visualize signals during a non-real-time simulation to visualize signals while running a real-time application.

• Parameter tuning — Use the Block Parameter dialog boxes to change

parameters in your application while it is running in real time.

Note Opening a dialog box for a source block causes Simulink to pause. While Simulink is paused, you can edit the parameter val ues. You must close the dialog box to have the changes take effect and allow Simulink to continue.

Typical uses for Real-Time Windows Target applications include

Coder™ code generation s oftw are (optional),

code

1-2

• Real-time control — Create a prototype of automotive, computer

peripheral, and instrumentation control systems.

• Real-time hardware-in-the-loop simulation — Create a prototype of

controllers connected to a physical plant. For example, the physical plant could be an automotive engine. Create a prototype of a plant connected to

Product Overview

an actual controller. For example, the prototyped plant could be an aircraft engine.

• Education — Teach concepts and procedures for modeling, simulating,

testing real-time systems, and iterating designs.

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1 Getting Started

Using This Guide

To benefit from this User’s Guide, you should be familiar with

• Using Simulink software and Stateflow software to create models as block

diagrams, and simulating those models using Simulink software

• The concepts and use of Real-Time Workshop code generation software to

create executable code

When using Real-Time Workshop code generation software and Real-Time Windows T arg et software, you do not need to program in C or other low-level programming languages to create and test real-time systems.

If You Are a New User — Begin with Chapter 1, “Getting Started”. This chapter g ives you an overview of Real-Time Windows Target features and the development environment. Next, read and try the examples in Chapter 3, “Basic Procedures”.

If You Are an Experienced User — We suggest you review the sections on signal tracing and signal logging in Chapter 3, “Basic Procedures”. After you are familiar with using Real-Time Window s Target software, read how to add I/O drivers to your Simulink model in Chapter 4, “Boards, Blocks, and Drivers”.

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Features

In this section...

“Real-Time Kernel” on page 1-5

“Real-Time Application” on page 1-6

“Signal Acquisition and Analysis” on page 1-7

“Parameter Tuning” on page 1-8

Real-Time Kernel

Real-Time Windows Target software uses a small real-time kernel to ensure that the real-time application runs in real time. The real-time kernel runs at CPU ring zero (privileged or kernel mode) and uses the built-in PC clock as its primary source of time:

• Timer interrupt — The kernel intercepts the interrupt from the PC clock

before the W indows interrupt to trigger the execution of the compiled model. As a result, the kernel is able to give the real-time application the h ig h est p ri ority available.

Note This behavior intercepts any calls to the Windows operating system. Consequently, you cannot use Win32 calls in your C-code S-function. For more information, see “Incompatibility with W in32 AP I Calls” on page A-4.

The kernel is provided as a kernel-mode driver. To achieve precise sampling, the kernel reprograms the PC clock to a higher frequency. Because the PC clock is also the primary source of time for the Windows operating system, the kernel sends a timer interrupt to the operating system at the original interrupt rate.

• Scheduler — The timer interrupt clocks a simple scheduler that runs

the executable. The number of tasks is equal to the number of sampling periods in the model with multitasking mode. With single-tasking mode, there is only one task. The maximum number of tasks is 32, and faster

operating system receives it. The k ernel then uses the

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1 Getting Started

tasks have higher priorities than slower tasks. For example, a faster task can interrupt a slower task.

During execution, the executable stores data in buffers. Later, the data in these buffers is retrieved by the Scope block. The scheduling, data storing, data transferring, and running the executable all run at CPU ring zero.

• Communication with hardware — The kernel interfaces and

communicates with I/O hardware using I/O driver blocks, and it checks for proper installation of the I/O board. If the board has been properly installed, the drivers allow your real-time application to run.

You can choose to have a driver block use values equal to voltage, normalize values from 0 to +1, normalize values from -1 to +1, or use the raw integer values from the A/D or D/A conversion press. Drivers also run at CPU ring zero.

• Simulink external mode — Com munication between Simulink software

and the real-time application is through the Simulink external mode interface module. This module talks directly to the real-time kernel, and is used to start the real-time application, change parameters, and retrieve scope data.

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Real-Time Application

The real-time application runs in real time on your PC computer and has the following characteristics:

• Compiled code — Created from the generated C-code using the Open

Watcom C/C++ compiler. For your convenience, this compiler is shipped with the Real-Time Windows Target software. No other third-party compiler is needed or can be used.

Note The Real-Time Windows Target software always uses the Open Watcom C/C++ compile r, even if yo u have specified some other compiler using the cannot be configured to use a compiler other than Open Watcom C/C++.

The Open Watcom source code is available under the terms of the Open Watcom License. For more information, visit http://www.openwatcom.org.

• Relation to your Simulink model — The executable contains a binary

form of all Simulink model components, connections between blocks, time dependencies, and variables in the Simulink blocks.

• Relation to the kernel — The executable must be loaded and executed

directly by the Real-Time Windows Target kernel. It cannot be executed without the kernel.

The kernel runs as a kernel-mode driver, intercepts timer interrupts from the PC clock, maintains clock signals for the Windows operating system, and ensures real-time execution of the real-time application. As a result, both the kernel and the real-time application run at CPU ring zero.

mex -setup command. Real-Time Windows Target software

Features

• Checksum — The Simulink model and the executable contain a checksum

value. The kernel uses this checksum value to determine if the Simulink model structure, at the time of code generation, is consistent with the real-time application structure during execution. This ensures that when you change parameters during an e xecution, the mapping of Simulink model parameters to the memory locations in the real-time application is correct.

If you make structural changes to your Simulink model, the Simulink checksum value will not match the executable checksum value. You will have to rebuild your executable before you can connect it to your Simulink model.

Signal Acquisition and Analysis

You can acquire, display, and save signals by using Simul ink Scope blocks and Simulink external mode. This lets you observe the behavior of your model during a simulation or your application while it runs in real time.

You can acquire signal data while running your real-time applications using

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1 Getting Started

• Signal Tracing — Process of acquir ing and visualizing signals during a

real-time run. It allows you to acquire signal data and visualize it on your computer while the executable is running.

• Signal Logging — Process for acquiring signal data during a real-time

run. After the run reaches its final time or you manually stop the run, you can plot and an a lyze the data .

You can save (log) data to variables in the MATLAB workspace or save data to your disk drive with MAT-files.

Signal logging di ff ers from signal tra c ing. With signal logging you can only look at a signal after a run is finished.

For more information, see “Logging Signals to the Base Workspace” on page 3-27 and “Logging Signals to a Disk Drive” on page 3-34.

Parameter Tuning

Change the parameters in your Simulink model and observe the effect of those changes during a simulation or while running an application in real time.

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Simulink external mode — You use Simulink external mode to connect your Simulink block diagram to your real-time application. The block diagram becomes a graphical user interface (GUI) to that executable.

Simulink external mode allows you to change parameters by editing the block diagram while running a simulation in external mode. New parameter values are automatically transferred to the real-time application while it is running.

Note Opening a dialog box for a source block causes Simulink to pause. While Simulink is paused, you can edit the parameter values. You must close the dialog box to have the chan g es take effect and allow Simulink to continue.

There are different types of model parameters that you can change while running your real-time application. For example, parameters include the amplitude of a gain and the frequency of a sine wave. After you connect your real-time application to your Simulink model, you can change parameters.

You can change these parameters before or while your real-time application is running by using one of the following methods:

• Block parameters — Change values in the dialog boxes associated with

the Simulink blocks.

• Block parameters for masked subsystems — Change values in

user-created dialog boxes associated with a subsystem.

• MATLAB variables — Create MATLAB variables that represent

Simulink block parameters, and then change parameter values by entering the changes through the MATLAB command line.

For more information about parameter tuning, see “Tuning Parameters” on page 3-44.

Features

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1 Getting Started

Hardware Environment

In this section...

“PC-Compatible Computer” on page 1-10

“Input/Output Driver Support” on page 1-10

PC-Compatible Computer

You can use any PC-compatible computer that runs Microsoft®Windows XP 32-bit, or Microsoft Windows Vista ™ 32-bit.

Your computer can be a desktop, laptop, or notebook PC.

Input/Output Driver Support

Real-Time Windows Target applications u s e standard and inexpensive I/O boards for PC-compatible computers. When running your models in real time, Real-Time Windows T arget software captures the sampled data from one or more input channels, uses the data as inputs to your block diagram model, immediately processes the data, and sends it back to the outside world through an output channel on your I/O board.

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I/O Boards

I/O boards — Real-Time Windows Target software supports a wide range of I/O boards. Some of the capabilities on a board may not be supported by Real-Time Windows Target software. Check Supported I/O Boards on the MathWorks Web site for an updated list of supported boards and capabilities.

I/O Driver Block Library

Real-Time Windows Target software provides a custom Simulink block library. The I/O driver block library contains universal drivers for supported I/O boards. These universal blocks are configured to operate with the library of supported drivers. This allows easy location of driver blocks and easy configuration of I/O boards.

You drag and drop a universal I/O driver block from the I/O library the same way as you would from a standard Simulink block library. And you connect

Hardware Environment

an I/O driver block to your model just as you would connect any standard Simulink block.

You create a real-time application in the same way as you create any other Simulink model, by using standard blocks and C-code S-functions. You can add input and output devices to your Simulink model by using the I/O driver blocks from the

rtwinlib library provided with the Real-Time Windows

Target software. This library contains the following blocks:

• Analog Input

• Analog Output

• Counter Input

• Digital Input

• Digital Output

• Encoder Input

• Frequency Output

• Packet Input

• Packet Output

• Stream Input

• Stream Output

The Real-Time Window s Target software provides driver blocks for more than 200 I/O boards. These driver blocks connect the physical world to your real-time application:

• Sensors and actuators are connected to I/O boards.

• I/O boards convert voltages to numer ical values and numerical values to

voltages.

• Numerical values are read from or written to I/O boards by the I/O drivers.

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1 Getting Started

Software Environment

In this section...

“Non-Real-Time Simulation” on page 1-12

“Real-Time Execution” on page 1-12

“Development Process” on page 1-13

Non-Real-Time Simulation

YoucreateaSimulinkmodelanduseSimulinksoftwareinnormalmodefor non-real-time simulation on your PC computer.

Simulink model — Create block diagram s with Simulink software by using simple drag-and-drop operations, and then enter values for the block parameters and select a sample rate.

Non-real-time simulation — Simulink software uses a computed time vector to step your Simulink model. After the outputs are computed for a given time value, the Simulink software immediately repeats the computations for the next time value. This process is repeated until it reaches the stop time.

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Because this computed time vector is not connected to a hardware clock, the outputs are calculated in nonreal time as fast as your computer can run. The time to run a simulation can differ significantly from real time.

Real-Time Execution

For re al-time execution on your PC computer, create a real-time application and use Simulink external mode, Real-Time Workshop code generation software, Real-Time Windows Target software, and the Open Watcom C/C++ compiler, to produce an executable that the kernel can run in real time. This real-time application uses the initial parameters available from your Simulink model at the time of code generation.

If you use continuous-time components in your model and create code with Real-Time Workshop code generation software, you must use a fixed-step integration algorithm. Real-Time Windows Target software provides the capabilities necessary for using the real-time resources on your computer

Software Environment

hardware. Based on your selected sample rate, Real-Tim e Windows Target software uses interrupts to step your application in real time at the proper rate. With each new interrupt, the executable computes all of the block outputs from your model.

Development Process

With Real-Time Windows Target rapid prototyping software, you can use your desktop PC with the MATLAB environment, Simulink software, Re al -Time Workshop code generation software, and Real-Time Windows Ta rget software to:

1 Design a control system — Use the MATLAB environment and Control

System Toolbox™ software to design and select the system coefficients for your controller.

2 Create a Simulink model —UseSimulinkblocksto graphically model

your physical system.

3 Run a simulation in nonreal time — Check the behavior of your model

before you create a real-time application. For example, you can check the stability of your model.

4 Create a real-time application — Real-Time Workshop code generation

software creates C code from your Simulink model. The Open Watcom C/C++ compiler compiles the C code to an executable that runs with the Real-Time Windows Target kernel.

5 Runanapplicationinrealtime— Your desktop PC is the target

computer to run the real-time application.

6 Analyze and visualize signal data — Use MATLAB functions to plot

data saved to the MATLAB workspace or a disk.

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1 Getting Started

Note Although Real-Time Windows Target applications ru n on the same

hardware as Windows, the Real-Time Windows Target kernel and the Win32 kernel are incompatible. When a Real-Time Windows Target application includes externally created code, such as a custom I/O driver block or a user-supplied S-function, the code cannot access any Win32 function. For more i nform ation, see “Incompatibility with Win32 API Calls” on page A-4.

1-14

System Concepts

In this section...

“Simulink External Mode” on page 1-15

“Data Buffers and Transferring Data” on page 1-16

Simulink External Mode

External mode requires a communications interface to pass external parameters. On the receiving end, the same communications protocol must be used to accept new parameter values and insert them in the proper memory locations for use by the real-time application. In some Real-Time Workshop targetssuchasTornado/VMEtargets,the communications interface uses TCP/IP protocol. In the case of a Real-Time Windows Target application, the host computer also serves as the target computer. Therefore, only a virtual device driver is needed to exchange parameters between the MATLAB environment, Simulink memory space, and memory that is accessible by the real-time application.

System Concepts

Signal acquisition — You can capture and display signals from your real-time application while it is running. Signal data is retrieved from the real-time application and displayed in the same Simulink Scope blocks you used for simulating your model.

Parameter tuning — You can change parameters in your Simulink block diagram and have the new parameters passed automatica lly to the r eal-time application. Simulink external mode changes parameters in your real-time application while it is running in real time.

Note that if you open a source block to change parameters, the simulation will pause while the block dialog box is o pen. You must close the dialog by clicking OK, which will resume the simulation.

As a user of Real-Time Windows Target rapid prototyping software, you will find that the requirements for setup are minimal. You start by enabling external mode . You then choose the Real-Time Workshop system target file from the Configuration Parameters dialog Real-Time Workshop tab. The MEX-file interface is automatically selected when you choose the targe t

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1 Getting Started

file. Then, after you have built the real-time application, you are ready for external mode operation.

Data Buffers and Transferring Data

At each sample interval of the real-time application, Simulink software stores contiguous data points in memory until a data buffer is filled. Once the data buffer is filled, Simulink software suspends data capture while the data is transferred back to the MATLAB environment through Simulink external mode. Your real-time application, however, continues to run. Transfer of data is less critical than maintaining deterministic real-time updates at the selected sample i nte rva l. Therefore, data transfer runs at a lower priority in the remaining CPU time after model computations are performed while waiting for another interrupt to trigger the next model update.

Data captured within one buffer is contiguous. When a buffer of data has been transferred, it is immediately plotted in a Simulink Scope block, or it can be saved directly to a MAT-file using the data archiving feature of the Simulink external mode.

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With data archiving, each buffer of data can be saved to its own MAT-file. The MAT-file names can be automatically incremented, allowing you to capture and automatically store many data buffers. Although points within a buffer arecontiguous,thetimerequiredtotransferdatabacktotheSimulink software forces an intermission for data collection until the entire buffer has been transferred and may result in lost sample points between data buffers.

Installation and Configuration

• “Required Products” on page 2-2

• “Related Products” on page 2-5

• “System Requirements” on page 2-6

• “Real-Time Windows Target Installed Files” on page 2-8

• “Initial Working Directory” on page 2-10

• “Real-Time Windows Target Kernel” on page 2-12

• “Testing the Installation” on page 2-17

2 Installation and Configuration

Required Products

In this section...

“Platform” on page 2-2

“The MATLAB Environment” on page 2-2

“Simulink Software” on page 2-2

“Real-Time Workshop Code Generation Software” on page 2-3

Platform

Real-Time Windows Target rapid prototyping software is a self-targeting system where the host and the target computer are the same computer. You can install it on a PC-compatible computer running Microsoft Windows XP 32-bit or Microsoft Windows Vista 32–bit.

Real-Time Windows Target software requires the installation of the MATLAB environment, Simulink software, Real-Time Workshop code generation software, and the Real-Time Windows Target kernel.

2-2

The MATLAB Environment

The MATLAB environment provides the design and analysis tools that you use when creating Simulink block diagrams. For information on using the MATLAB environment, see Getting Started with M ATLAB, which exp lains how to work with data and how to use MATLAB functions. For a reference describing the functions supplied with the MATLAB environment, see the MATLAB Function Reference.

Simulink Software

Simulink softw a re provides an environment where you model your physical system and controller as a block diagram. You create the block diagram by using a mouse to connect blocks and a keyboard to edit block parameters. C code S-functions are supported by Real-Time Workshop code generation software.

Required Products

Unsupported Simulink blocks —YoucanuseReal-TimeWindows Target software with most Simulink blocks including discrete-time and continuous-time systems. Real-Time Windows Target software does not support blocks that do not run in real time, nor does it support To File blocks.

Limitations with Real-Time Workshop code generation software — When you use a continuous-time system and generate code with Real-Time Workshop code generation software, you must use a fixed-step integration algorithm. How ever, M-code S-functions are not supported.

Real-Time Windows Target I/O driver blocks — With Real-Time Windows Target so ftw are , you can remove the physical system model and replace it with I/O driver blocks connected to your sensors and actuators. The Real-Time Windows Targe t I/O li b ra ry supports more than 200 boards.

Note Some of the functions on a board may not be supported by Real-Time Windows Target software. Check the MathWorks Web site for an updated list of supported boards and functions at Supported I/O Boards.

Simulink documentation — For information on Simulink software, see Simulink User’s Guide, which explains how to connect blocks to build models and change block parameters. It also provides a reference that describes each block in the standard Simulink library.

Real-Time Workshop Code Generation Software

Real-Time Workshop code generation software provides the utilities to convert your Simulink models into C code, and then, with the Open Watcom C/C++ compiler,compilethecodeintoareal-timeexecutable.

Real-Time Windows Target software is designed for maximum flexibility during rapid prototyping. This flexibility allows parameter tuning and signal tracing during a real-time run, but increases the size of the generated code. However, Real-Time Workshop code generation software provides other code formats that generate the more compact code needed for embedded applications.

2-3

2 Installation and Configuration

Real-Time Workshop documentation — For information on code generation, see the Real-Time Workshop User’s Guide.

2-4

Related Products

2-5

2 Installation and Configuration

System Requirements

In this section...

“Platform Requirements” on page 2-6

“Hardware Requirements” on page 2-6

“Software Requirements” on page 2-6

Platform Requirements

The Real-Time Windows Target software requires a PC-compatible computer.

Hardware Requirements

The following table lists the minimum hardware resources that the Real-Time Windows Target software requires on your computer.

Hardware Description

2-6

CPU

Periph

RAM

When you are using a laptop computer, Real-Time Window s Target software provides a portable environment where your computer uses PCMCIA cards to interfacetorealworlddevices.

erals

Pentium or higher in a desktop, laptop, or compact PCI or PC104 industrial computer

Hard disk drive with 16 megabytes of free space

Data acquisition board (for a list of supported boards, see Supported I/O Boards)

DVD drive

egabytes minimum, 256 megabytes

128 m

ommended

rec

Software Requirements

Real-Time Windows Target software has certain prerequisites that must be met for proper installation and execution.

System Requirements

The following table lists the products you need to install on your computer to run Real-Time Windows Target software:

• Microsoft Windows XP 32–bit or Microsoft Windows Vista 32–bit

• MATLA B 7.9

• Simulink 7.4

• Real-Time Workshop 7.4

• Real-Time Windows Target 3.4

The Real-Time Windows Target software does not support the Simscape™ or SimDriveline™ p roducts.

2-7

2 Installation and Configuration

Real-Time Windows Target Installed Files

You can install Real-Time Windows Target software as part of the regular installation process documented in MathWorks™ installation guides. This section describes installed files that areuniquetoReal-TimeWindowsTarget software. When using the product, you may find it helpful to know where these files are located.

• MATLAB working directory — Simulink models (

Real-Time Windows Target executable (

Note Select a working directory outside the MATLAB root. See “Initial Working Directory” on page 2-10.

• Real-Time Workshop project directory — The Real-Time W orkshop

C-code files (

• Real-Time Windows Target Files — The files included with Real-Time

Windows Target software are located in the directory

matlabroot\toolbox\rtw\targets\rtwin

• Open Watcom C/C++ compiler directory — The Open Watcom C/C++

compiler files are located in a subdirectory called

Real-Time Windows Target software provides files to help Real-Time Workshop code generation s oftware create C code from your Simulink model and compile that code to a real-time executable:

• System Target File (

code by Real-Time Windows Target software.

model.c, mo del.h) are in a subdirectory called model_rtwin.

rtwin.tlc) — Defines the process of generating C

model.rwd)

model.mdl)andthe

openwat.

2-8

• Template Makefile and Makefile (

template m akefile serves as a template for generating the real makefile, which the make utility uses during model compilation. During the automatic build procedure, the from the template makefile

model_name.mk.

rtwin.tmf, model_name.mk)—The

make command extracts information

rtwintmf.m and generates the makefile

Real-Time Windows Target™ Installed Files

• Make Command (make_rtw.m)—Thestandardmake command supplied

with Real-Time Workshop code generation software.

Other files provided with Real-Time Windows Target software include

• I/O drivers (

*.rwd) — Binaries for I/O device drivers. Real-Time Windows

Target software does not link the driver object files with your real-time executable. The drivers are loaded into memory and run by the kernel separately.

• Simulink external mode interface (

rtwinext.mex*)—MEX-filefor

communicating between Simulink external mode and the Real-Time Windows Target kernel.

Simulink external mode uses the MEX-file interface module to download new parameter values to the real-time model and to retrieve signals from the real-time m odel. You can display these signals in Simulink Scope blocks.

• Kernel install and uninstall commands (

.m scripts to install and uninstall the Real-Time Windows Target kernel

rtwintgt.m, rtwho.m)—

and check installation.

2-9

2 Installation and Configuration

Initial Working Directory

In this section...

“Working Directory Location Requirement” on page 2-10

“Setting the Working Directory from the Desktop Icon” on page 2-10

“Setting the Working Directory from the MATLAB Environment” on page 2-10

Working Directory Location Requirement

Set your MATLAB working directory outside the MATLAB ro ot directory. The default MATLAB root directory is version number.

Setting the Working Directory from the Desktop Icon

Your initial w orking directory is specified in the shortcut file you use to start the MATLAB environment. To change this initial directory, use the following procedure:

c:\matlabN,whereN is the MATLAB

2-10

1 Right-click the MATLAB desktop icon, or from the program menu,

right-click the MATLAB shortcut.

2 Click Properties.IntheStart in text box, enter the directory path you

want the MATLAB environment to use initially outside the MATLAB root directory.

3 Click

OK, and then start the MATLAB environment. To check your

ing directory, type

work

pwd or cd

Setting the Working Directory from the MATLAB Environment

Use the following procedure as an alternative, but temporary, procedure for setting your MATLAB working directory:

1 In the MATLAB Command Window, type

cd c:\mwd

2 Check the current working directory, type

The MATLAB Command Window displays

ans = c:\mwd or c:\mwd

Initial Working Directory

2-11

2 Installation and Configuration

Real-Time Windows Target Kernel

In this section...

“About the Kernel” on page 2-12

“Installing the Kernel” on page 2-12

“Uninstalling the Kernel” on page 2-14

About the Kernel

The Real-Time Windows Target software includes a real-time kernel that interfaces with the Windows operating system. The Real-Time Windows Target kernel assigns the highest priority of execution to your real-time executable, which allows it to run without interference at the selected sample rate. During real-time execution of your model, the kernel intervenes when needed to ensure that the model is given priority to use the CPU to execute each model update at the prescribed sample times. Once a model update completes, the kernel releases the CPU to run any other Windows based application that might need servicing.

2-12

Installing the Kernel

During software installation, all Real-Time Windows Target software is copied onto your hard drive, but the Real-Time Windows Target kernel is not automatically installed into the operating system. You must install the kernel before you can run a Real-Time Windows Target application. Installing the kernel configures it to start running in the background each time you start your computer. The following procedure describes how to use the command

rtwintgt -install. Youcanalsousethecommandrtwintgt -setup

instead. To install the kernel:

1 In the MATLAB Command Window, type:

rtwintgt -install

or:

a Click the MATLAB Start button.

Real-Time Windows Target™ Kernel

b Select Links and Targets > Real-Time Windows Target > Install

real-time kernel

The M ATLAB Command Window displays one of these messages:

You are going to install the Real-Time Windows Target kernel.

Do you want to proceed? [y] :

or:

There is a different version of the Real-Time Windows Target kernel installed.

Do you want to update to the current version? [y] :

2 Type y to continue ins talling the k ernel, or n to cancel installation without

making any changes.

If you type

y, the MATLAB environment installs the kernel and displays

the message:

The Real-Time Windows Target kernel has been successfully installed.

3 If a message appears asking you to restart your computer, do so before

attempting to use the kernel, or your Real-Time Windows Target model will not run correctly.

4 After installing the kernel, verify that it was correctly installed by typing:

rtwho

The MATLAB Command Window should display a message that shows the kernel version number, followed by pe rformance, timeslice, and other information.

Once the kernel is installed, you can leave it insta ll ed. The kernel remains idle after you have installed it, which allows the Windows operating system to control the execution of any standard Windows based application, including Internet browsers, word processors, the MATLAB environment, and so on. The kernel becomes active when you begin execution of your model, and becomes idle again after m odel execution completes.

2-13

2 Installation and Configuration

Uninstalling th

If you encounter can uninstall th has no impact on remains on your

eKernel

any problems with Real-Time Windows Target software, you

e kernel. Once uninstalled, the kernel is no longer active and

the operation of your computer. The kernel executable file

hard drive so that you can later reinstall it. To uninstall

the kernel:

1 In the MATLAB C

rtwintgt -uninstall

ommand Window or a DOS window, type:

or:

a Click the MA

b Select Lin

real-time

TLAB Start button.

ks and Targets > Real-Time Windows Target > Uninstall kernel

The MATLAB Command Window displays the message:

You are going to uninstall the Real-Time Windows Target kernel.

Do you want to proceed? [y]:

2 Type y to continue uninstalling the kernel, or n to cancel uninstallation

without making any changes.

2-14

If you type

y, the MATLAB environment uninstalls the kernel by removing

it from memory, then displays the message:

al-Time Windows Target kernel has been successfully uninstalled.

The Re

3 After uninstalling the kernel, verify that it was correctly uninstalled: Type:

rtwh

The M ATLA B environment should display the following message.

Real-Time Windows Target™ Kernel

If the uninsta

llation fails, see “Forci bl y Uninstalling the Kernel” on page 2-16 .

Uninstalling the Kernel Without MATLAB

Uninstalli Windows Tar andneedtou

rtwintgt -uninstall

The kerne see “Forc

ng the MATLAB environment does not u nins tall the Real-Time

get kernel. If you have uninstalled the MATLAB environment

ninstall the kernel, launch a DOS command shell and type:

l should then uninstall from your system. If the uninstallation fails,

ibly Uninstalling the Kernel” on page 2-16 .

2-15

2 Installation and Configuration

Forcibly Uninstalling the Kernel

If you cannot uninstall the kernel with rtwintgt -uninstall, something has corrupted the Real-Time Windows Target kernel service. To uninstall the kernel:

1 In the MATLAB Command Window or a DOS command shell, type:

2 Restart the computer before attempting any other action, including

Use thekernelfail. Thecommandleavesthecomputerinaninconsistentstate that cannot be relied on and does not post relevant error me ssage s.

rtwintgt -forceuninstall

The command forcibly deregisters the kernel from the operating system without deleting any files.

reinstalling the kernel.

rtwintgt -forceuninstall only when all other attempts to uninstall

2-16

Note Never execute rtwintgt -forceuninsta ll without immediately rebooting, after which you can reinstall the Real-Time Windows Target kernel as described in “Installing the Kernel” on page 2-12.

Testing the Installation

In this section...

“About Installation Testing” on page 2-17

“Running the Model rtvdp.mdl” on page 2-17

“Displaying Status Information” on page 2-19

“Detecting Excessive Sample Rates” on page 2-20

“Demo Library” on page 2-21

About Installation Testing

Real-Time Widows Target includes several demo models. You can use the demo models to test your installation. Demo models simplify testing of your installation since they are configured with settings that include the correct target, scope settings, sample time, and integration algorithm. To see these demo models, type

Testing the Installation

rtwtdemo in the M ATLA B Command Window.

OnceyouhavecompletedtheinstallationoftheReal-TimeWindowsTarget software and kernel, we recom m end a quick test by running the model

rtvdp.mdl. If you change your installation, we also recomm end doing this

test as a quick check to confirm that the Real-Time Windows Target software is still working. To open the demo model, type Command Window, or launch MATLAB Online Help and choose Real-Time Windows T arget > Demos > Real-Time Van der Pol Simulation.

rtvdp in the MATLAB

Running the Model rtvdp.mdl

The model rtvdp.mdl does not have any I/O blocks, so that you can run this model regardless of the I/O boards in your computer. Running this model will test the installation by running Real-Time Workshop code generation software, Real-Time Windows Target software, and the Real-Time Windows Target kernel.

After you have installed the Real-Time Windows Target kernel, you can test the entire installation by building and running a real-time application. The Real-Time Windows Target software includes the model already has the correct Real-Time Workshop options selected for you:

rtvdp.mdl,which

2-17

2 Installation and Configuration

1 In the MATLAB Command Window, type

rtvdp

The Simulink model rtvdp.mdl window opens.

2-18

2 From the Tools menu, choose Real-Time Workshop > Build Model.

The MATLAB Command Window displays the following messages:

### Starting Real-Time Workshop build for model: rtvdp

### Invoking Target Language Compiler on rtvdp.rtw

...

### Compiling rtvdp.c

...

### Created Real-Time Windows Target module rtvdp.rwd.

### Successful completion of Real-Time Workshop build procedure

for model: rtvdp

3 From the Simulation menu, click External,andthenclickConnect to

target.

The M ATLA B Command Window displays the following message:

Model rtvdp loaded

Testing the Installation

4 From Simulation menu, click Start Real-Time Code.

The Scope window displays the output signals. If your Scope window looks like the next figure, you have successfully installed the Real-Time Windows Target software and have run a real-time application.

5 From Simulation menu, click Stop Real-Time Code.

The real-time application stops running, and the Scope window stops displaying the output signals.

Displaying Status Information

The Real-Time Windows Target software provides the command rtwho for displaying the kernel version number, followed by perform ance, timeslice, and other information. To see this information, in the MATLAB Command Window type

rtwho

The command dis plays several lines of information in the MATLAB Command Window. Some possible lines and their interpretations are:

2-19

2 Installation and Configuration

This message indicates that the MATLAB environment and other non-real-time applications (for example, a word processor) are able to run at 100% perform ance because no real-time applications are currently executing. When a real-time application is executing, the MATLAB performance is at a value below 100%. For example, if the MATLAB performance = 90.0%, then the real-time application is using 10% of the CPU time. We recommend that you select a sample rate so that of at least 80%.

The kernel time slice period is the current frequency of the hardware timer interrupt. One millisecond is the maximum value for models with large sample times (slow sampling rate) or when an application has not been built. This value changes when you select sampling ti mes less than 1 millisecond.

MATLAB performance = 100.0%

rtwho returns a MATLAB performance

Kernel timeslice period = 1 ms

TIMERS: Number Period Running

10.01Yes

2-20

The indicated timer(s) exist on your system with the period and run status shown for each timer.

DRIVERS: Name Address Parameters

Humusoft AD512 0x300 []

ecg 0 []

The indicated device driver(s) are installed on your system at the address and with the parameter(s) shown for each driver.

Detecting Excessive Sample Rates

If your specified sample r a t e is too fast, the Real-Time Windows Target software detects and reports this during real-time execution. Sampling rates exceeding 10 kHz can be achieved on Pentium computers. Once the model is running, you can issue the Window to observe the system performance.

For example, the following lines show that MATLAB performance has decreased because the system is overloaded:

rtwho command in the MATLAB Command

Testing the Installation

MATLAB performance = 77.1% Kernel timeslice period = 0.0 01 ms

We recommend that MATLAB performance not fall below 80%.

Demo Librar y

The demo library includes models with preset values and dialog boxes. These models include a configuration of examples that use no I/O, A/D only, A/D and D/A in a simple signal processing demo, as well as in a simple control demo. Examples that use I/O blocks require you to configure the Adapter block to match the I/O board installed in your computer. To see these demo models from the MATLAB environment:

1 Type rtwtdemo in the MATLAB Command Window.

The Real-Time Windows Target Demos window displays.

2 From the list, select the demo to open it.

2-21

2 Installation and Configuration

2-22

Basic Procedures

• “Using Simulink Models” on page 3-2

• “Using Real-Time Applications” on page 3-14

• “Logging Signals to the Base Workspace” on page 3-27

• “Logging Signals to a Disk Drive” on page 3-34

• “Tuning Parameters” on page 3-44

3 Basic Procedures

Using Simulink Models

In this section...

“About Simulink Models” on page 3-2

“Creating a Model” on page 3-2

“Configuring a Model” on page 3-6

“Running a Simulation” on page 3-12

About Simulink Models

A Simulink model is a graphical representation of your physical system. You create a Simulink model for a non-real-time simulation of your system, and then you use the Simulink model to create a real-time application.

Creating a Model

You need to create a Simulink model before you can run a simulation or create a real-time application. This procedure explains how to create a simple Simulink model. You can use this model as an example to learn other procedures that are useful with Real-Time Windows Target software.

3-2

1 In the MATLAB Command Window, type

simulink

The Simulink Library Browser opens. The left pane shows a hierarchy of libraries and block categories, with the Simulink library at the top. The right pane shows the b lock s available in the category selected on the left . See “Library Browser” for more information.

2 Choose File>New>Model,orclicktheNew model buttononthetoolbar.

mpty Simulink window opens:

An e

Using Simulink®Models

3 In the left pane of the Simulink Library Browser window, select Simulink

>Sources. Click and drag a Signal Generator block from the browser to

the Simulink window.

Select Continuous. Click and drag a Transfer Fcn block to the Simulink window.

Select Sinks. Click and drag a Scope block to the Simu link window.

4 Connect the Signal Generator output to the Transfer Fcn input by

clicking-and-dragging a line between the blocks. Likewise, connect the Transfer Fcn output to the Scope input.

5 Double-click the Transfer Fcn block. The Block Parameters dialog box

opens. In the Numerator te xt box, enter:

[10000]

In the Denominator text box, enter

[1 70 10000]

Your Block Parameters dialog box looks similar to the next figure.

3-3

3 Basic Procedures

3-4

6 Click OK.

7 Double-click the Signal Generator block. The Block Parameters dialog box

opens. From the Wave form list, select

square.

In the Amplitude text box, enter

In the Frequency text box, enter

From the Units list, select rad/sec.

Your Block Parameters dialog box looks similar to the next figure.

Using Simulink®Models

8 Click OK.

The next figure shows the completed Simulink block diagram, with toolbar and status bar not shown:

9 From the File menu, click Save As. The Save As dialog box opens. In the

File name textbox,enterafilenameforyourSimulinkmodelandclick Save. For example, type

in_model

rtw

The Simulink software saves your model in the file rtwin_model.mdl.

To specify a default Real-Time Windows Target configuration set for your model, see “Specifying the D efault Configuration Set” on page 3-7. If you

3-5

3 Basic Procedures

activate this configuration set for your model, you can build your real-time application later without setting additional configuration parameters.

To manually configure your model, continue to “Entering Configuration Parameters M anually” on page 3-8, following. That section teaches you how to enter configuration parameters for your Simulink model, then leads you into procedures for entering scope parameters and running a non-real-time simulation of the model.

Model Referencing

The Real-Time Windows Target software supports model re fere ncing. See “Referencing a Model” in the Simulink User’s Guide guide for more information.

File System Input/Output

Like mos t real-time environments, the Real-Time Windows Target software does not include a file system. Therefore, a Simulink model intended for use in a Real-Time Windows Target application cannot use any blocks, such as the To File or From File block, that generate file I/O calls such as

fopen or printf.

3-6

If a Real-Time Windows Target model contains any block that tries to perform file system I/O, an error could occur when you try to compile the model, generate code for it, or use External Mode with it. Even if no error occurs, the block has no effect on either simulation or code execution.

To log signal data w ithout needing a file system, use the techniques described in “Logging Signals to a Disk Drive” on page 3-34. See “Running a Real-Time Application” on page 3-23 for information about using External Mode to execute a Real-Time Windows Target application.

Configuring a Model

After you create a Simulink model, you can enter configuration parameters for the model. These parameters control many properties of the model for simulation and code generation. This section contains the essential information you need when setting configuration parameters for a Real-Time Windows Target application. For complete information about Simulink

Using Simulink®Models

configuration parameters, see “Setting Up Configuration Sets” and “Configuration Parameters Dialog Box”.

A configuration set is a named set of values for model parameters, such as solver type and simulation start or stop time. Every new model is created with a default configuration set, called

Configuration, that initially specifies

default values for the model’s model parameters. You can subsequently cre ate additional configuration sets and associate them with the model, as described in “Referencing Config uration Sets”.

Theeasiestwaytospecifyconfiguration parameters for a Real-Time Windows Target m odel is to programmatically assign the default Real-Time Windows Target configuration set, as described in “Specifying the Default Configuration Set” on page 3-7. You can also set parameters manually, as described in “Entering Configuration Parameters Manually” on page 3-8. Other sections describe setting configuration patterns for specific purposes.

Specifying the Default Configuration Set

After you create a Simulink model, you can use the rtwinconfigset function to specify a default Real-Time Windows Target configuration set for the model. In most cases, using parameter values that the model needs. The following procedure uses the Simulink model

rtwin_model.mdl as an exa m ple and assumes you have

already loade d that m odel (see “Creating a Model” on page 3-2):

rtwinconfigset provides all the configuration

1 If you have not already saved the model, from the File menu, click Save

As. The Save As dialog box opens. In the File name text box, enter a file name for your Sim ulink model and click Save. For example, type

rtwin_model

The Simulink software saves your model in the file rtwin_model.mdl.

2 In the MATLAB Command Window, type

rtwinconfigset('rtwin_model')

The default Real-Time Windows Target configuration set, R T Win, is now active for the

rtwin_model model. (Alternatively, you can set the default

Real-Time Windows Target configuration set by setting the Configuration

3-7

3 Basic Procedures

Parameters System target file option to rtwin.tlc.) You do not need to perform any other configuration for a Real-Time Windows Target application.

3 Save the model.

See “Creating a Real-Time Application” on page 3-19 for a description of how to build your Real-Time Windows Target application .

To revert to the default configuration set, Configuration, or any other configuration set you have for the model, use Model Explorer. This is an alternative tool that you can use to enter simulation parameters for a model. See the Simulink documentation for a description of how to use Model Explorer.

Note Your model uses a Real -Time Windows Target configuration set when you change the System target file value to a Real-Time Windows Target one, such as

rtwin.tlc or rtwinert.tlc. The softw are creates the Real-Time

Windows Target configuration set, RTWin or RTWinERT, only i f one does not already exist.

3-8

Entering Configuration Parameters Manually

The configuration parameters give information to Simulink softw a r e for running a simulation. This procedure uses the Simulink model

rtwin_model.mdl as an example and assumes you have already l oa ded t ha t

model:

1 In the Simulink window, and from the Simulation menu, click

Configuration Parameters. In the Configuration Parameters dialog

box, click the Solver tab.

The Solver pane opens.

2 In the Start time field, enter 0.0.IntheStop time field, enter the amount

of time you want your model to run. For example, enter

3 From the Type list, choose Fixed-ste p. Real-Time Workshop code

generation software does not support variable step solvers.

10.0 seconds.

Using Simulink®Models

4 From the Solver list, choose a solver. For example, choos e the general

purpose solver

5 In the Fixedstepsizefield, enter a sample time. For example, enter

0.001 seconds for a sam p l e rate of 1000 samples/second.

6 From the Tasking Mode list, choose SingleTasking. (For models with

blocks that have diffe rent sample times, choose

ode5 (Dormand-Prince).

MultiTasking.)

Your Solver pane looks similar to the next figure.

7 Do one

• Clic

of the follo wing:

k Apply to apply the changes to your model and leave the dialog

pen.

box o

k OK to apply the changes to your model and close the dialog box.

Entering Scope Parameters for Signal Tracing

enter o r change scope parameters to specify the x-axis and y-axis in a

You

ope w indow. Other properties include the number of graphs in one Scope

ndow and the sample time for models with discrete blocks.

3-9

3 Basic Procedures

After you add a Scope block to your Simulink model, you can enter the scope parameters for s ignal tracing:

1 In the Simulink window, doubl e- c li ck the Scope block.

A Scope window opens.

2 Click the Parameters button.

A Scope para

3 Click the General tab. In the Number of axes field, enter the number of

graphs you want in one Scope window. For example, enter

meters dialog box opens.

1 for a single

graph. Do not select the floating scope check box.

In the Time range field, enter the upper value for the time range. For example, enter

From the S Enterin continu

Fixed st

ous time block. If you have discrete blocks in your model, enter the

ep size you entered in the Configuration Parameters dialog box.

1 second. From the Tick labels list, choose all.

ampling list, choose

0 indicates that the Simulink software evaluates this block as a

Sample time and enter 0 in the text box.

Your Scope parameters dialog box looks similar to the next figure.

3-10

Using Simulink®Models

4 Do one of the following:

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click OK to apply the changes to your model and close the dialog box.

5 In the Scope window, point to the y-axis shown in the next figure, and

right-click.

6 From the pop-up m enu, click Axes Properties.

7 The Scope properties: axis 1 dialog box opens. In the Y-min and Y-max

text boxes, enter the range for the y-axis in the Scope window. For example, enter

-2 and 2 asshowninthenextfigure.

8 Do one of the following:

3-11

3 Basic Procedures

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click OK to apply the changes to your model and close the dialog box.

Running a Simulation

You use Simulink normal mode to run a non-real-time simulation. Running a simulation lets you observe the behavior of your model in nonreal time.

After you load your Simulink model into the M ATLAB workspace, you can run a simulation. This procedure uses the Simulink model as an example and assumes you have loaded that model:

1 In the Simulink window, doubl e- c li ck the Scope block.

The Simulink software opens a Scope window with an empty graph.

2 From the Simulation menu:

• Select Normal mode simulation.

rtwin_model.mdl

3-12

• Choose Start to begin sim u lation .

The Simulink software runs the simulation and plots the signal data in the Scope window.

During the simulation, the Scope window displays the samples for one time range, increases the time offset, and then displays the samples for thenexttimerange.

Using Simulink®Models

3 Do one of the following:

• Let the simulation run to the stop time.

• From the Simulation menu, click Stop.

The simulation stops. The MATLAB environment does not display any messages.

3-13

3 Basic Procedures

Using Real-Time Applications

In this section...

“About Real-Time App lication s” on page 3-14

“Entering Simulation Parameters” on page 3-14

“Entering Scope Parameters for Signal Tracing” on page 3-17

“Creating a Real-Time Application” on page 3-19

“Entering A d dition a l Scope P ara m eters for Signal Tracing” on page 3-20

“Running a Real-Time Application” on page 3-23

“Running an Application from the Command Line” on page 3-25

About Real-Time Applications

You create a real-time application to let your system run while synchronized to a real-time clock. This allows your system to control or interact with an external system. This is necessary if you use your s ystem to stabilize a physical plant. The first step is to create a Simulink Model, as described in the previous section, “Using Simulink Models” on page 3-2.

3-14

Entering Simulation Parameters

After you create a Simulink model, you can enter simulation parameters for use by Real-Time Workshop code generation software for creating C code and building a real-time application.

This procedure uses the Simulink model assumes you have already loaded that model:

1 In the Simulink window, and from the Simulation menu, click

Configuration Parameters.

2 Click the Real-Time Workshop node.

e Real-Time Workshop pane opens.

rtwin_model.mdl as an example and

Using Real-Time Applications

3 In the Target selection section, click the Browse button at the RTW

system target file list.

The System Target File Browser opens.

4 Select the system target file for building a Real-Time Windows Target

application, and click OK.

The dialog a template ma

Real-Time W

utomatically enters the system target file

kefile

rtwin.tmf,andthemakecommandmake_rtw into the

orkshop pane.

If you have the Real-Time Workshop

Embedded Coder™ product, you can

rtwin.tlc,the

build a n ERT target application. To build an ERT target application, in the

Target selection section, click the Browse button at the System target file list. Click

rtwinert.tlc,andthenclickOK.

Although not visible in the Real-Time Workshop pane, when you click OK you also configure the external target interface MEX file

rtwinext.

This allows external mode to pass new parameters to the real-time application and to return signal data from the real-time application. The data is displayed in Scope blocks or saved with signal logging.

Your Re

al-Time Workshop pane looks similar to the next figure.

3-15

3 Basic Procedures

Do not sel paramete of RAM or R paramete more mem inline p

5 Click the Hardware Implementation node. The following values are

set by default:

• Device vendor —

• Device type — 32-bit x86 compatible

• Emulation hardware — N one

ect Inline param eters on the Optimization node. Inlining

rs is used for custom targets when you want to reduce the amount

OM with embedded systems. Also, if you select inlining

rs, you disable the parameter tuning feature. Since PCs have

ory than embedded systems, we recommend that you do not

arameters.

Generic

3-16

Using Real-Time Applications

6 Do one of the

• Click Appl

box open.

• Click OK t

Entering

You ente Scope wi window a

If you e proced

After param

1 In th

2 Click the Parameters button.

r or change scope parameters to format the x -axis and y-axis in a

ndow. Other parameters include the number of graphs in a one Scope

nd whether the scope is connected to a continuous or discrete model.

ntered the scope parameters for running a simulation, you can skip this

ure. This information is repeated here if you did n ot run a simulation.

you add a Scope block to your Simulink model, you can enter the scope

eters for signal tracing:

e Simulink window, double-click the Scope block.

A Scope window opens.

following:

y to apply the changes to your model and leave the dialog

o apply the changes to your model and close the dialog box.

Scope Parameters for Signal Tracing

3-17

3 Basic Procedures

A Scope paramete

3 Click the General tab. In the Number of axes field, enter the number of

graphs you want in one Scope window. For example, enter

rs dialog box opens.

1 for a single

graph. Do not select the floating scope check box.

In the Time range field, enter the upper value for the time range. For example, enter

From the Sam Entering continuous

Fixed step

1 second. From the Tick labels list, choose all.

pling list, choose Sample time and enter

ndicates that the Simulink software evaluates this block as a

0 i

0 in the text box.

time block. If you have discrete blocks in your model, enter the

size you entered in the Configuration Parameters dialog box.

Your Scope parameters dialog box looks similar to the next figure.

3-18

4 Do one of the following:

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click OK to apply the changes to your model and close the dialog box.

Using Real-Time Applications

5 In the Scope window, point to the y-axis and right-click. From the menu,

click Axes Properties.

The Scope properties: axis 1 dialog box opens.

6 In the Y-min and Y-max text boxes enter the range for the y-axis in the

Scope window. Forexample,enter

7 Do one of the following:

-2 and 2.

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click OK to apply the changes to your model and close the dialog box.

Creating a Real-Time Application

The Real-Time Workshop code generation softw are creates C code from your Simulink model, th en the Open Watcom C/C++ compiler compiles and links that C code into a real-time application.

After you enter parameters into the Configuration Parameters dialog box for use by the Real-Time Workshop code generation software, you can build a real-time application. This procedure uses the Simulink model

rtwin_model.mdl as an example, and assum es you have loaded that model:

1 In the Simulin k window, from the Tools menu, point to Real-Time

Workshop,andthenclickBuild Model.

build process does the following:

The

• The

Real-Time Workshop code generation software creates the C code

sou

rce files

rtwin_model.c and rtwin_mo del. h.

3-19

3 Basic Procedures

• Themakeutilitymake_rtw.exe creates the makefile rtwin_model.mk

from the template makefile rtwin.tmf.

• Themakeutility

rtwin_model.rwd using the makefile rtwin_model.mk created above.

The file real-time application. You can run the real-time application with the Real-Time Windows Target kernel.

2 Connect your Simulink model to your real-time application. See “Entering

Additional Scope Parameters for Signal Tracing” on page 3-20.

After you create a real-time application, you can exit the MATLAB environment, start the MATLAB environment again, and then connect and run the executable without having to rebuild.

rtwin_model.rwd is a binary file that we refer to as your

make_rtw.exe builds the real-time application

Entering Additional Scope Parameters for Signal Tracing

Simulink external mode connects your Simulink model to your real-time application. This connection allows you to use the Simulink block diagram as a graphical user interface to your real-time application.

After you have created a real-time application, you can enter scope parameters for signal tracing with Simulink external mode:

1 In the Simulation window, and from the Simulation menu, click

Configuration Parameters.

3-20

2 Select the Real-Time Windows Target node.

The Real-Time Windows Target pane opens.

3 Select the External mode check box.

The MEX-file name label s hould have an entry of

rtwinext.mex* is supplied with the Real-Time Windows Target software

to work with Simulink external mode and support uploading s ignal data and downloading parameter values.

The Real-Time Windows Target pane should appear as follows.

rtwinext.TheMEX-file

Using Real-Time Applications

4 Click OK.

5 In the Sim

Mode Con

ulation window, and from the Tools menu, click External

trol Panel.

The External Mode Control Panel dialog box opens.

3-21

3 Basic Procedures

6 Click the Signal & Triggering button.

3-22

The Exter

7 Select the Select all check box. From the Source list, choose manual.

nal Signal & Triggering dialog box opens.

From the Mode list, choose normal.

The

X under Signal selection indicates that a signal is tagged for data

collection, and

8 In the D

For exa time o

9 Sele

mple, to specify a sample rate of 1000 samples/second and a stop

f 10 se conds, enter

10001

ct the Armwhenconnectingtotargetcheck box.

T indicates that the signal is tagged a s a trigger signal.

uration field, enter the number of sample points in a data buffer.

If you do not select this check box, data is not displayed in the Scope window.

The External Signal & Triggering dialog box looks like this:

10 Do one of the following:

Using Real-Time Applications

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click Close to apply the changes to your model and close the dialog box.

You must click the Apply or Close button on the External Signal & Triggering dialog box for the changes you made to take effect. Generally it is no t necessary to rebuild your re al-tim e application.

Running a Real-Time Application

You run your real-time application to observe the behavior of your model in real tim e with the generated code. The process of connecting co n sists of

• Establishing a connection between your Simulink model and the kernel to

allow exchange of commands, parameters, and logged data.

• Running the application in real time.

After you build the real-time application, you can run your model in real time. This procedure uses the Simulink model and assumes you have created a real-time application for that m odel:

rtwin_model.mdl as an example,

3-23

3 Basic Procedures

1 From the Simulation menu:

• Select External mode simulation.

• Choose Connect To Target.

(You can conne

The MATLAB Command Window displays the message

Model rtwin_model loaded

2 From the Simulation menu, choose Start Real-Time Code.

(You can also start the code from the toolbar by clicking

The Simulink software runs the execution and plots the signal data in the Scope window.

In this example, the Scope window displays 1000 samples in 1 second, increases the time offset, and then displaysthesamplesforthenext1 second.

Note Transfer of data is less critical than calculating the signal outputs at the selected sample interval. Therefore, data transfer runs at a lower priority in the remaining CPU time after real-time applicat ion computations are performed while waiting for another interrupt to trigger the next real-time application update. The result may be a loss of data points displayed in the Scope window.

ct to the target from the toolbar by clicking

3-24

3 Do one of the following:

• Let the execution run until it reaches the stop time.

• From the Simulation menu, click Stop Real-time Code.

The real-time application stops.

Using Real-Time Applications

4 In the Sim

Disconne

5 From the Simulation menu, click External.

ulation window, and from the Simulation menu, click

ct From Target.

The MATLAB Command Window displays the message

Model r

twin_model unloaded

Running an Application from the Command Line

YoucanusetheMATLABcommand-lineinterfaceasanalternativetousing the Simulink GUI. Enter commands directly in the MATLAB Command Window or save them in a script file.

After you build the real-time application, you can run your model in real time. This procedure uses the Simulink model and assumes you have created a real-time application for that m odel:

1 In the MATLAB Command Window, type

rtwin_model.mdl as an example,

3-25

3 Basic Procedures

set_param(gcs,'SimulationMode','external')

The Simulink software changes to external mode.

2 Type

set_param(gcs,'SimulationCommand','connect')

The MATLAB environment loads the real-time application, connects it to the Simulink block diagram, and displays the message

Model rtwin_model loaded

3 Type

set_param(gcs,'SimulationCommand','start')

The Simulink software starts running the real-time application.

4 Type

3-26

set_param(gcs,'SimulationCommand','stop')

The Simulink software stops the real-time application.

Logging Signals to the Base Workspace

In this section...

“About Signal Logging” on page 3-27

“Entering Scope Parameters” on page 3-27

“Entering Signal and Triggering Properties” on pag e 3-29

“Plotting Logged Signal Data” on page 3-31

About Signal Logging

Signal logging to the base workspace is the process of saving (logging) data to a variable in your MATLAB w orkspace. This allows you to use MATLAB functions for data analysis and MATLAB plotting functions for visualization. You can save data to a variable during a simulation or during an execution.

Simulink external mode does not support data logging with Outport blocks in your Simulink model. This means you do not enter or select parameters on the Data I/O tab in the Configu rati o n Parameters dialog bo x.

Logging Signals to the Base Workspace

To use signal logging with a Real-Time Windows Target application, you must add a Scope block to your Simulink model.

Entering Scope Parameters

Data is saved to the MATLAB workspace through a Simulink Scope block. Scope block parameters need to be set for data to be saved. After you create a Simulink model and add a Scope block, you can enter the scope parameters for signal logging to the MATLAB workspace. This procedure uses the Simulink model already loaded that model.

Note If you entered the scope parameters for running a simulation, you may want to look ov er this pro cedure, because the Scope paramete rs dialog box is related to the External Signal and Triggering dialog box.

rtwin_model.mdl as an example, and assumes you have

3-27

3 Basic Procedures

1 In the Simulink window, doubl e- c li ck the Scope block.

A Scope window opens.

2 On the toolbar, click Parameters.

A Scope Parameters dialog box opens.

3 Click the Data history tab.

4 Do one of the following:

• If you a re running a simulation, select the Limitdatapointstolast

check box, and enter the number of sample points to save.

• If you are running an execution, do not select the Limit data points to

last check box.

3-28

The Limit data points to last check box is related to the Duration value in t he External S ig nal and Trig g ering dialog box. The smaller of either value limits the number of sample points saved to the MATLAB workspace. Wh en you are using Real-Time Windows Target software, use the Duration valuetosetthenumberofsamplepointsyousave. Toset the Duration value, see the next section.

5 Select the Save data to workspace check box. In the Variable name

text box, enter the name of a MATLAB variable. The default name is

ScopeData.

6 From the Format list, choose Structure with time, Structure,orArray

(compatible w ith V2.0-2.2). For example, to save the sample times and signal values at those times, choose

Structure with time.

Your Data history pane looks similar to the next figure.

Logging Signals to the Base Workspace

7 Do one of the following:

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click OK to apply the changes to your model and close the dialog box.

When you modify anything in the Scope parameters dialog box, you must click the Apply or OK button for the changes to take effect, and you must rebuild your real-time application before connecting and starting it. If you do not rebuild, an error dialog box will open. If you do not click Apply,your executable will run, but it will use the old settings.

The rea includ model c realafter

Ente

Data Sign area

cedure.

pro

er y ou create a Simulink model and add a Scope block, you can enter the

Aft

gnal and triggering properties for logging to the MATLAB workspace. This

son why you need to rebuild is because the model checksum

es settings from the Scope block used for signal logging. If the

hecksum does not match the checksum in the generated code, the

time application cannot run. Always rebuild your real-time application

changing Scope parameters.

ring Signal and Triggering Properties

is saved to the MATLAB workspace through a Simulink Scope block.

al and triggering properties need to be set only when you are running

l-time application. If you are running a simulation, you can skip this

3-29

3 Basic Procedures

procedure uses the Simulink model rtwin_model.mdl as an example and assumes you have already loaded that model:

1 In the Simulink window, and from the Tools menu, click External Mode

Control Panel.

The External Mode Control Panel dialog box opens.

2 Click the Signal & Triggering button.

The E xternal Signal & Triggering dialog box opens.

3 Click the Select all button. From the Source list, choosemanual.From

the

Mode list, choose normal.

The

X under Signal selection designates that a signal has been tagged

for data collection, and

T designates that the signal has been tagged as

atriggersignal.

4 In the Duration field, enter the number of sample points in a data buffer.

For example, if you have a sample rate of 1000 samples/second and a stop time of 10 seconds, you could enter

3-30

10000

The Duration value is related to the Limit data points to last value in the Scope parameters dialog box. The smaller of either value limits the number of sample points saved to the MATLA B workspace. We recomm end that you do not select the Limit data points to last check box; use the

Duration valuetosetthenumberofsamplepointssaved. Toclearthe Limit data points to last check box, see “Entering Scope Parameters”

on page 3-27.

If you e nter a value less than the total number of sample points, you will lose sample points during the time needed to transfer values from thedatabuffertotheMATLABworkspace. TheReal-TimeWindows

Logging Signals to the Base Workspace

Target software ensures that points are continuous only within one buffer. Between buffers, because of transfer tim e, some samples will be omitted.

We also recommend setting the time axis for Simulink Scope blocks equal to the sample interval (in seconds) times the number of points in each data buffer. This setting will display one buffer of data across the entire Simulink Scope plot.

The External Signal & Triggering dialog box looks similar to the next figure.

5 Do one of the following:

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click Close to apply the changes to your model and close the dialog box.

Plotting Logged Signal Data

You can use the M ATLAB plotting functions for visualizing non-real-time simulated data or real-time application data.

3-31

3 Basic Procedures

After running your real-time application and logging data to the M ATLAB workspace, you can plot the data. This procedure uses the Simulink model

rtwin_model.mdl as an example, and assumes you saved your data to the

variable

1 In the MATLAB Command Window, type

ScopeData.

ScopeData

The MATLAB Command Window shows the structure of the variable

ScopeData.ThevariableScopeData is a MATLAB structure containing

fields for the time vector, signal structure, and a string containing the block name.

ScopeData =

time: [10000x1 double]

signals: [1x1 struct]

blockName: 'rtwin_model/Scope'

To list the contents of the structure signals, type

3-32

ScopeData.signals

The MATLAB Command Window shows the structure of the variable

ScopeData.signals. This structure contains one or more vectors of signal

data depending on the number of signal inputs to the Scope block.

ans =

values: [10000x1 double]

dimensions: 1

label: '' title: []

plotStyle: 1

2 To plot the first 1000 points, type

plot(ScopeData.time(1:1000),ScopeData.signals.values(1:1000))

The MATLAB environment plots the first 1000 samples from 0.0000 to

0.9990 second.

Logging Signals to the Base Workspace

3 The variable ScopeDa ta is not automatically saved to your hard disk. To

save the variable

ScopeData,type

save ScopeData

The MATLAB environment saves the scope data to the file Sc opeD ata.mat.

3-33

3 Basic Procedures

Logging Signals to a Disk Drive

In this section...

“About Signal Logging” on page 3-34

“Entering Scope Parameters” on page 3-34

“Entering Signal and Triggering Properties” on pag e 3-37

“Entering Data Archiving Parameters” on page 3-39

“Plotting Logged Signal Data” on page 3-41

About Signal Logging

Logging signals to a disk drive is th e process of saving (logging) data to a variable in your MATLAB workspace and then saving that data to a MAT-file on your disk drive. This allows you to use MATLAB functions for data analysis and MATLAB plotting functions for visualization.

3-34

Using the data archiving feature p r ovided in the External Mode Control Panel, you can save data to a file during execution. Simulink external mode

does not support data logging with Outport blocks in your Simulink model. This means you do not enter or select parameters on the Data I/O pane in the Configuration Parameters dialog box.

To use the data archiving feature with a Real-Time W in d ows Target application, you must add a Scope block to your Simulink model, and you mustexecuteareal-timeapplication.

Entering Scope Parameters

YousavedatatoadiskdrivebyfirstsavingthedatatotheMATLAB workspace through a Simulink Scope block. You need to set scope block parameters for data to be saved.

After you create a Simulink model and add a Scope block, you can enter the scope parameters for signal logging to a disk drive. This procedure uses the Simulink model already loaded that model.

rtwin_model.mdl as an example, and assumes you have

Logging Signals to a Disk Drive

Note If you entered the scope parameters for running a simulation, you may want to look over this procedure, because the Scope parameters dialog box is related to the External Signal & Triggering dialog box and the Data Archiving dialog box.

1 In the Simulink window, doubl e- c li ck the Scope block.

A Scope window opens.

2 On the toolbar, click the Parameters button.

A Scope parameters dialog box opens.

3 Click the

4 Do one of the following:

Data history tab.

• If you are running a simulation, you can select the Limit data points

to last check box, and enter the number of sample points to save.

• If you are running an execution, do not select the Limit data points to

last check box.

The Limit data points to last check box is related to the Duration value in the External Signal & Triggering dialog box. The smaller of either value limits the number of sample points saved to the MA TLAB workspace. When using Real-Time Window s Target software, we recommend that you use the Duration valuetosetthenumberofsamplepointsyousave. To set the Duration value, see “Entering Signal and Triggering Properties” on page 3-37.

ect the Save data to workspace check b ox. In the Variable name

5 Sel

t box, enter the name of a MATLAB variable. The default name is

tex

Sco

peData

3-35

3 Basic Procedures

The Scope parameters dialog box is related to the Data Archiving dialog box. In the Scope parameters dialog box, you must select the Save data to workspace check box to be able to save data to a disk drive, for two reasons:

• The data is first transferred f rom the data buffer to the M ATLA B

workspace before being written to a MAT-file.

• The Variable name entered in the Scope parameters dialog box is the

same as the one in the MATLAB workspace and the MAT-file.

If you do not select the Save data to workspace check box, the MAT-files for data logging will be created, but they w ill be e mpty .

6 From the Format list, c hoose eitherStructure with time, Structure,or

Array(compatible with Version 2.0 through Version 2.2). For example, to

save the sample times and signal values at those times, choose

with time

.YourData history pane looks similar to the next figure.

Structure

3-36

7 Do one of the following:

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click OK to apply the changes to your model and close the dialog box.

Logging Signals to a Disk Drive

You must rebuild your real-time application before connecting and starting the application with changed settings. If you do not rebuild after making changes, an error will occur.

Entering Signal and Triggering Properties

Data is saved to a disk drive by first saving the data to the MATLAB workspace through a Simulink Scope block. Signal and triggering properties need to be set when running a real-time application.

After you create a Simulink model and add a Scope block, you can enter the signal and triggering properties fordataloggingtoadiskdrive. This procedure uses the Simulink model assumes you have already loaded that model:

1 In the Simulink window, and from the Tools menu, click External Mode

Control Panel.

The External Mode Control Panel dialog box opens.

rtwin_model.mdl as an example, and

2 Click the Signal & Triggering button.

The E xternal Signal & Triggering dialog box opens.

3 Click the Select all button. From the Source list, choosemanual.From

the

Mode list, choose normal.

The

X under Signal selection designates that a signal has been tagged

for data collection, and

T designates that the signal has been tagged as

atriggersignal.

4 In the Duration field, enter the number of sample points in a data buffer.

For example, if you have a sample rate of 1000 samples/second and a stop time of 10 seconds, then enter

10000

3-37

3 Basic Procedures

The Duration valuespecifiesthenumberofcontiguous points of data to be collected in each buffer of data. W e recommend that you enter a Duration value equal to the total number of sample points you need to collect for a run. If you enter a value much less than the total number of sample points, you may lose logging sample points due to the time needed to transfer values from the data buffer to the MATLAB workspace.

The External Signal & Triggering dialog box looks similar to the next figure.

3-38

5 Do one of the following:

• Click Apply to apply the changes to your model and leave the dialog

box open.

• Click Close to apply the changes to your model and close the dialog box.

You must click the Apply or Close button on the External Signal & Triggeringdialogboxforthechangesyoumadetotakeeffect,butyoudo not have to rebuild your real-time application.

Logging Signals to a Disk Drive

Entering Data Ar

The Data Archivi box. In the Scope workspace chec

• The data is fir

workspace bef

• The Variable n

same as the on thedatatobe parameter t

If you do not parameters they will b

After you c Paramete

1 In the Sim

Mode Con

The External Mode Control Panel dialog box opens:

eempty.

rsfordataloggingtoadiskdrive:

ng dialog box is related to the Scope parameters dialog

k box to be able to save data to a disk drive, for two reasons:

st transferred from the scope data buffer to the MATLAB

ore being written to a MAT-file.

eintheMATLABworkspaceandtheMAT-file. Enabling

saved enables a variable named with the Variable name

obesavedtoaMAT-file.

select the Save data to workspace check box in the Scope

dialog box, the MAT-files for data logging will be created, but

reate a Simulink model, you can enter the Data Archiving

ulation window, and from the Tools menu, click External

trol Panel.

chiving Parameters

parameters dialog box, you must select the Save data to

ame entered in the Scope parameters dialog box is the

3-39

3 Basic Procedures

2 Click the Data Archiving button.

3-40

The Exter to specif

3 Select the Enable archiving check box.

4 In the Directory text box, enter the path to a directory on your disk drive.

For example, if your MATLAB working directory is named

c:\mwd

5 In the File text box, enter the file name prefix for the data files to be

nal Data Archiving dialog box opens. This dialog box allows you

y data a rchiving options.

mwd,enter

saved. For example, enter

data

The MATLAB environment names the files data_0.mat, data_1.mat,etc. The number of files equals the total sample points. For example, if you set Duration to

ect the Append file suffix to variable names check box.

6 Sel

Total sample points, then only one file is created.

Logging Signals to a Disk Drive

Within each MAT-file, a variable is saved with the same name you entered in the Variable name text box (Data history pane on the Scope parameters dialog box). By selecting the Append file suffix to variable names check box, the same suffix that is added to the MAT-file is added to the variable name. For example, if you entered the variable name

ScopeData, then within the file data_0.mat will be a variable

ScopeData_0.

Your External Data Archiving dialog box looks similar to the next figure.

7 Click the Close button.

The parameters you entered are applied to your model.

There is no Apply button with this dialog box. You must click the Close button for the changes you make to take effect.

Plotting Logged Signal Data

You can use the MATLAB plotting functions for visualization of your non-real-time simulated data or your real-time executed data.

After running your real-time application and logging data to a disk drive, you can plot the data. This procedure uses the Simulink model as an example, and assumes you saved your data to the variable ScopeData:

1 In the MATLAB Command Window, type

ScopeData

rtwin_model.mdl

3-41

3 Basic Procedures

The MATLAB Command Window shows the structure of the variable

ScopeData.ThevariableScopeData is a MATLAB structure containing the

fields time vector, signal structure, and a string containing the block name.

ScopeData =

time: [10000x1 double]

signals: [1x1 struct]

blockName: 'rtwin_model/Scope'

2 To list the MAT-files saved to your disk drive , type

dir *.mat

The MATLAB Command Window shows the MAT-files in your current working directory.

ScopeData.mat

3 To clear the MATLAB workspace and load the scope data, type

3-42

clear load ScopeData who

The MATLAB Command Window displays:

Your variables are: ScopeData

4 To plot the first 1000 points, type

plot(ScopeData.time(1:1000), ScopeData_0.signals.values(1:1000))

The MATLAB environment plots the first 1000 samples from 0.0000 to

0.9990 second.

Logging Signals to a Disk Drive

3-43

3 Basic Procedures

Tuning Parameters

In this section...

“About Parameter Tuning” on page 3-44

“Changing M odel Parameters” on page 3-45

About Parameter Tuning

Simulink external mode connects your Simulink model to your real-time application. The block diagram becomes a graphical user interface to the real-time application You can change parameter values while running the real-time application by changing the values in

• Block parameters — Change block parameters by changing the values

in the dia log bo xes associated with the Simulink blocks. Once you change a value, and click OK, the new value is downloaded to the real-time application.

3-44

• MATLAB variables — Change MATLAB v ariables by entering the

changes through the MATLAB command line, and then press Ctrl+D for the changes to be downloaded to your executable. An alternative method to download parameters is to click Update Diagram from the Edit menu in your Simulink window. Simply changing the value of the MATLAB variable at the MATLAB command line is not sufficient for the Simulink software to know that the value has changed.

Simulink external mode also supports side-effects functions. For example, given an expression in a Gain block of the resulting value is exported to the real-time application during execution.

2*a+b, the expression is evaluated and

Tuning Parameters

When a parameter in a Simulink model is changed, the communication module

rtwinext.mex* transfers the data to the external real-time

application and changes the model parameters. Only the parameters that do not result in model structure modification can be changed. If the structure is modified, you must recompile the model. Model structure changes are detected automatically using model checksum and reported to the MATLAB Command Window to avoid conflicts.

Changing Model Parameters

You must use Simulink external mode to change model parameters. While external mode is running, you can open Simulink blocks and change parameter values. External mode will transferthenewvaluetothereal-time application.

Note Opening a dialog box for a source block causes Simulink to pause. While Simulink is paused, you can edit the parameter values. You must close the dialog box to have the chan g es take effect and allow Simulink to continue.

After you start running your real-time application, you can change para m eters and observe the changes to the signals. To start a real-time application, see “Running a Real-Time Application” on page 3-23.

The following procedure uses the Simulink model

rtwin_model.mdl as

an example. It assum es you have created a real-time application and are executing it.

1 From the Simulation menu, click Start Real-Time.

The real-time execution starts running and signal data is displayed in the Scope window.

3-45

3 Basic Procedures

2 From the Simulink block diagram, double-click the Transfer Function block.

The Block Parameters: Transfer Fcn dialog box opens:

3-46

3 In the Denominator field, change 70 to 30.ClickOK.

Tuning Parameters

The effect of changing a block parameter is shown in the Scope window.

3-47

3 Basic Procedures

3-48

Boards, Blocks, and Drivers

• “Introduction” on page 4-2

• “Using I/O Boards” on page 4-3

• “Using I/O Driver Blocks” on page 4-10

• “Using Analog I/O Drivers” on page 4-16

• “Using Vector CAN Dr ivers” on page 4-21

4 Boards, Blocks, and Drivers

Introduction

Real-Time W indo ws Target software includes driver blocks for more than 200 I/O boards. These driver blocks connect the physical world to your real-time application.

4-2

Using I/O Boards

In this section...

“About I/O Boards” on page 4-3

“Installing and Configuring I/O Boards and Drivers” on page 4-3

“ISA Bus Board” on page 4-7

“PCI Bus Board” on page 4-7

“PC/104 Board” on page 4-8

“Compact PCI Board” on page 4-8

“PCMCIA Board” on page 4-9

About I/O Boards

Typically I/O boards are preset from the factory for certain base addresses, voltage levels, and unipolar or bipolar modes of operation. Boards often include switches or jumpers that allow you to change many of these initial settings. For information about setting up and installing any I/O board, read the board manufacturer’s documentation.

Using I/O Boards

For a n online list of all I/O boards that Real-Time Windows Target software supports, see Supported I/O Boards.

Installing and Configuring I/O Boards and Drivers

A R eal-Time Windows Target model connects to a board by including an I/O driver block. This block provides an interface to the board’s device driver and all b oard-specific settings. The device drivers included with the Real-Time Windows Target software usually provide the same flexibility of settings offered by the board manufacturer. You can enter I/O board settings by using the I/O Block Parameters dialog box; setting jumpers and switches on the board; or both. The three types of board settings are:

• Software selectable — Specify the desired settings in the I/O Block

Parameters dialog box. The driver writes the settings you specify to the board. Examples include A/D gain inputs and selecting unipolar or bipolar D/A outputs.

4-3

4 Boards, Blocks, and Drivers

• Hardware selectable and software readable — Specify the desired

• Hardware selectable, but not software readable —Setjumpersor

You can configure a Real-Time Windows Target model to use an I/O board whether or not the board exists in the computer, but you will not be able to run the model u ntil th e board is installed with any jumpers or switches correctly set. Details o f installation and configuration depend on the data transfer direction and the specific board, but are essentially similar in all cases. Details for various types of boards and drivers appear later in this chapter.

settings by configuring jumpers or switches on the board. The driver reads the settings you selected and displays them in the I/O Block Parameters dialog box.

switches on the physical board, and then enter the same settings in the I/O Block Parameters dialog box. These entries must match the hardware jumpers or switches you set on the board. This type of setting is necessary when the board manufacturer does not provide a means for the I/O driver to write or read all board settings. Examples include base address, D/A gain, a nd differential or single-ended A/D inputs.

4-4

The following instructions use the Humusoft

AD512 I/O board as an example, configure the board for analog input, and assume that you have physically configured and installed the board in your computer before you add its driver to your model. Cu stomize the steps t o provide the results that you need.

To install and configure an I/O board and its driver,

1 Install the board in the computer, setting any jumpers or switches as

needed.

2 In the model window, choose View > Library Browser to display the

Simulink Library Browser.

3 Clone an appropriate Input or Output driver block to your model from the

Real-Time Windows Target library.

4 Double-click the cloned I/O driver block.

The I/O Block Parameters dialog box opens. For an Analog Input block, the dialog box initially looks like this:

Mathworks REAL-TIME WINDOWS TARGET 3 Reference

Specifications and Main Features

Frequently Asked Questions

User Manual