Mathworks XPC TARGET 4 user guide

xPC Target™ 4

User’s Guide

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xPC T arget™ User’s Guide

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Revision History

September 1999 First printing New for Version 1 (Release 11.1) November 2000 Online only Revised for Version 1.1 (Release 12) June 2001 Online only Revised for Version 1.2 (Release 12.1) September 2001 Online only Revised for Version 1.3 (Release 12.1+) July 2002 Online only Revised for Version 2 (Release 13) June 2004 Online only Revised for Version 2.5 (Release 14) August 2004 Online only Revised for Version 2.6 (Release 14+) October 2004 Online only Revised for Version 2.6.1 (Release 14SP1) November 2004 Online only Revised for Version 2.7 (Release 14SP1+) March 2005 Online only Revised for Version 2.7.2 (Release 14SP2) September 2005 Online only Revised for Version 2.8 (Release 14SP3) March 2006 Online only Revised for Version 2.9 (Release 2006a) May 2006 Online only Revised for Version 3.0 (Release 2006a+) September 2006 Online only Revised for Version 3.1 (Release 2006b) March 2007 Online only Revised for Version 3.2 (Release 2007a) September 2007 Online only Revised for Version 3.3 (Release 2007b) March 2008 Online only Revised for Version 3.4 (Release 2008a) October 2008 Online only Revised for Version 4.0 (Release 2008b) March 2009 Online only Revised for Version 4.1 (Release 2009a) September 2009 Online only Revised for Version 4.2 (Release 2009b) March 2010 Online only Revised for Version 4.3 (Release 2010a)

Target and S cope Objects

Target Objects ..................................... 1-2

What Is a Target Object?

........................... 1-2

Contents

Scope Objects

What Is a Scope Object? Scope Object Types

..................................... 1-3

............................ 1-3

................................ 1-4

Targets and Scopes in the MATLAB Interface

Working with Target Objects ....................... 2-2

Accessing Help for Target Objects Creating Target Objects Deleting Target Objects Displaying Target Object Properties Setting Target Object Properties from the Host PC Getting the Value of a Target Object Property Using the Method Syntax with Target Objects

Working with Scope Objects

Accessing Help for Scope Objects Displaying Scope Object Properties for a Single Scope Displaying Scope Object Properties for All Scopes Setting the Value of a Scope Property Getting the Value of a Scope Property Using the Method Syntax with Scope Objects Acquiring Signal Data with Scopes of Type File Acquiring Signal Data into Multiple, Dynamically Named

Files with Scopes of Type File

Advanced Data Acquisition Topics

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

............................ 2-3

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

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

...... 2-4

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

.......... 2-6

........................ 2-7

..................... 2-7

....... 2-8

................. 2-9

................. 2-10

........... 2-11

......... 2-11

..................... 2-12

.................... 2-14

.... 2-7

Signals and Parameters

Monitoring S ignals ................................ 3-2

Introduction Signal Monitoring with xPC Target Explorer Signal Monitoring with the MATLAB Interface Monitoring Stateflow States

...................................... 3-2

........... 3-2

......... 3-9

......................... 3-10

Signal Tracing

Introduction Signal Tracing with xPC Target Explorer Signal Tracing with the MATLAB Interface Signal Tracing with xPC Target Scope Blocks Signal Tracing with Simulink External Mode Signal Tracing with a Web Browser

Signal Logging

Introduction Signal Logging with xPC Target Explorer Signal Logging in the MATLAB Interface Signal Logging with a Web Browser

Parameter Tuning and Inlining Parameters

Introduction Parameter Tuning with xPC Target Explorer Parameter Tuning with the M ATLAB Interface Parameter Tuning with Simulink External Mode Parameter Tuning with a W eb Browser Saving and Reloading Application Parameters with the

MATLAB Interface

Inlined Parameters

..................................... 3-15

...................................... 3-15

.............. 3-15

............ 3-39

.......... 3-48

........... 3-50

.................. 3-54

.................................... 3-56

...................................... 3-56

.............. 3-56

.............. 3-59

.................. 3-63

......... 3-65

...................................... 3-65

........... 3-66

......... 3-69

............... 3-75

.............................. 3-75

................................ 3-78

....... 3-72

vi Contents

Nonobservable Signals and Parameters

............. 3-85

Booting from a DOS Device

DOSLoader Mode .................................. 4-2

Introduction DOSLoader Mode Setup Restrictions Creating a Target Application for DOSLoader Mode Creating DOSLoader Files with a Command-Line

Interface

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

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

...................................... 4-3

...................................... 4-4

..... 4-4

Creating a DOS System Disk

........................ 4-6

Embedded Option

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

xPC Target Embedded Option Modes

Introduction Standalone Mode Overview Restrictions

Embedded Option Setup

Creating a DOS System Disk

Stand-Alone Target Setup

Before You Start Updating Environment Properties Creating a Kernel/Target Application Copying the Kernel/Target Application to the Target PC

Flash Disk

...................................... 5-3

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

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

........................... 5-7

........................ 5-7

.......................... 5-8

.................................. 5-8

..................................... 5-10

................ 5-3

.................... 5-9

................. 5-9

vii

Software E nvironment an d Demos

Using Environme

Introduction Getting a List o

PCs

Changing Envir

Explorer

Changing Envi

Interface for

xPC Target De

Introductio To Locate or

Target

Creati Displa

Values

Setti

Prope Addin Remo Gett Chan Work

Env

nt Properties and Functions

........

...................................... 6-2

f Environment P ropertie s for Default Target

........................................... 6-2

onment Properties with xPC Target

....................................... 6-3

ronment Properties with a Command-Line

DefaultTargetPCs

mos

.................................

......................................

Edit a Demo Script

Working wi

Environment Comma nd-Line Interface

ng Target PC Environment Object Containers

ying Target PC Environment Object Property

th Target PC Environments

...................

.....................

.......

.....

........................................

ng Target PC Environment Collection Object

rties

g Target PC Environment Collection Objects

ving Target PC Environment Collection O bjects

ing Target PC Environment Object Names

ging Target PC Environment Object Defaults ing with Particular Target PC Object

ironments

.....................................

......

....

.........

......

..................................

6-2

6-7

6-9 6-9

6-11

7-2 7-2

7-2

7-3 7-4 7-4 7-4 7-5

7-5

viii Contents

ing the Target PC Command-Line Interface

Target PC Command-Line Interface ................. 8-2

Introduction ...................................... 8-2

Using Target Application Methods on the Target PC Manipulating Target Object Properties from the Target

........................................... 8-3

Manipulating Scope Objects from the Target PC Manipulating Scope Object Properties from the Target

........................................... 8-5

Aliasing with Variable Commands on the Target PC

..... 8-2

........ 8-4

..... 8-6

Working with Target PC Files and File Systems

Introduction ...................................... 9-2

FTP and File System Objects

Using xpctarget.ftp Objects

Overview Accessing Files on a Specific Target PC Listing the Contents of the Target PC Folder Retrieving a File from the Target PC to the Host PC Copying a File from the Host PC to the Target PC

Using xpctarget.fs Objects

Overview Accessing File Systems from a Specific Target PC Retrieving the Contents of a File from the Target PC to the

Host PC Removing a File from the Target PC Getting a List of Open Files on the Target PC Getting Information about a File on the Target PC Getting Information about a Disk on the Target PC

........................................ 9-5

........................................ 9-9

....................................... 9-11

....................... 9-4

......................... 9-5

................ 9-6

........... 9-7

....... 9-8

.......................... 9-9

....... 9-10

.................. 9-14

.......... 9-14

..... 9-7

...... 9-15

..... 9-16

Graphical User Interfaces

xPC Target Interface Blocks to Simulink Models ..... 10-2

Introduction Simulink User Interface Model Creating a Custom Graphical Interface To xPC Target Block From xPC Target Block Creating a Target Application Model Marking Block Parameters Marking Block Signals

...................................... 10-2

...................... 10-2

................ 10-3

............................... 10-4

............................ 10-5

.................. 10-6

.......................... 10-7

............................. 10-9

xPC Target Web Browser Interface

Web Browser Interface ............................. 11-2

Introduction Connecting the Web Interface Through TCP/IP Connecting the Web Interface Through RS-232 Using the Main Pane Changing WW W Properties Viewing Signals with a W eb Browser Viewing Parameters with a Web Browser Changing Access Levels to the Web Browser

...................................... 11-2

......... 11-2

......... 11-3

.............................. 11-7

......................... 11-9

................. 11-10

.............. 11-11

........... 11-11

x Contents

Interrupts Versus Polling

Polling Mode ...................................... 12-2

Introduction xPC Target Kernel Polling Mode Interrupt Mode Polling Mode Setting the Polling Mode Restrictions Introduced by Polling Mode

...................................... 12-2

..................... 12-2

................................... 12-3

..................................... 12-5

........................... 12-7

............... 12-10

Controlling the Target Application ................... 12-13

Polling Mode Performance Polling Mode and Multicore Processors

.......................... 12-14

................ 12-15

Incorporating Fortran Code into the xPC Target

Environment

Before You Start ................................... 13-2

Introduction Simulink Demos Folder Prerequisites Steps to Incorporate Fortran in the Simulink Software for

xPC Target

...................................... 13-2

............................ 13-2

..................................... 13-3

.................................... 13-3

Step-by-Step Example of Fortran and xPC Target

In This Example Creating an xPC Target Atmosphere Mo del for Fortran Compiling Fortran Files Creating a C-MEX Wrapper S-Function Compiling and Linking the Wrapper S-Function Validating the Fortran Code and Wrapper S-Function Preparing the Model for the xPC Target Application

Build Building and Running the xPC Target Application

......................................... 13-14

.................................. 13-5

............................ 13-7

............... 13-8

.... 13-5

.. 13-5

........ 13-12

... 13-14

...... 13-16

Vector CANape Support

Vector CANape .................................... 14-2

Introduction xPC Target and Vector CANape Limitations

Configuring the xPC Target and Vector CANape

Software

Setting Up and Building the Model

...................................... 14-2

........... 14-3

........................................ 14-4

................... 14-4

Creating a New Vector CANape Project to Associate with a

Particular Target Application Configuring the Vector CANape Device Providing A2L (ASAP2) Files for the Vector CANape

Database

...................................... 14-10

..................... 14-6

................ 14-7

Event Mode Data Acquisition

Guidelines Limitations

....................................... 14-11

...................................... 14-11

....................... 14-11

Frequently Asked Questions

Overview ......................................... 15-2

BIOS Settin gs

Booting Issues

Is Your Host PC MATLAB Interface Halted? Is Your Target PC Unable to Boot? Is the Target PC Halted?

Communications

Is There Communication Between Your PCs? Why Does the xPC Target System Lose Connection with the

Host PC When Downloading Some Models? How Can I Diagnose Network Problems with the xPC

Target System?

..................................... 15-3

..................................... 15-4

........... 15-4

................... 15-4

........................... 15-5

.................................. 15-6

........... 15-6

.......... 15-7

................................. 15-11

xii Contents

Installation, Configuration, and Build

Troubleshooting

Troubleshooting xpctest Results Troubleshooting B uild Issues

General xPC Target Troubleshooting

General I/O Troubleshooting Guidelines Can I View the Contents of the Target PC Display on the

Host PC?

................................. 15-12

..................... 15-12

........................ 15-19

................ 15-21

............... 15-21

...................................... 15-22

Why Do Attempts to Run My Model Cause CPU O verload

Messages on the Target PC?

How Can I Obtain PCI Boa rd Information for My xPC

Target System?

What Sample Time Can I Expect from the xPC Target

Software?

WhyIsMyRequestedxPCTargetSampleTimeDifferent

from the Measured Sample Time?

Why Did I Get Error -10: Invalid File ID on the Target

PC?

........................................... 15-30

Can I Write Custom xPC Target Device Drivers? Can I Create a Stand-Alone xPC Target Application to

Interact with a Target Application? Can Signal Outputs from Virtual Blocks Be Tagged? WhyHastheStopTimeChanged? Why Do I Get a File System Disabled Error? Can the Target PC Hard Drive Contain M u l tip le

Partitions? Why Does the getparamid Function Return Nothing? How Do I Handle Register Rollover for xPC Target Encoder

Blocks? Why Do I Get Compile Error When Compiling Models?

........................................ 15-33

................................. 15-27

...................................... 15-28

..................................... 15-33

...................... 15-22

.................. 15-28

........ 15-30

................. 15-31

..... 15-31

.................... 15-32

........... 15-32

.... 15-33

... 15-34

Getting Updated xPC Target Releases and Help

How to Get Updated xPC Target Releases Are You Working with a New xPC Target Release? Refer to the MathWorks Support Web Site Refer to the Documentation

......................... 15-36

............. 15-35

............. 15-36

...... 15-35

Target PC Command-Line Interface Reference

Target PC Commands .............................. 16-2

Introduction Target Object Methods Target Object Property Comm ands Scope Object Methods Scope Object Property Commands Aliasing with Variable Commands

...................................... 16-2

............................. 16-2

................... 16-3

.............................. 16-4

.................... 16-6

................... 16-7

xiii

Function Reference

Software Environment ............................. 17-2

GUI

Test

Target A pplication Objects

Scope Objects

File and File System Objects

xPC Target Environment Collection Object

xPC Target Utilities

.............................................. 17-3

.............................................. 17-4

......................... 17-5

..................................... 17-7

........................ 17-8

Directories FTP

............................................. 17-8

File System

....................................... 17-8

...................................... 17-8

................................ 17-11

.......... 17-10

Functions

xiv Contents

Index

Target and Scope Objects

Before you can work with xPC Target™ target and scope objects, you should understand the concept of target and scope objects.

• “Target Objects” on page 1-2

• “Scope Objects” on page 1-3

1 Target and Scope Objects

Target Objects

What Is a Target Object?

The xPC Targ et software uses a target object (of class xpctarget.xpc)to represent the target kernel and y our target application. Use target object functions to run and control real-time applications on the target PC with scope objects to collect signal data.

See “Function Reference” and “Functions” for a reference of the target functions.

An understanding of the target object properties and methods will help you to control and test your application on the target PC.

A target object on the host PC represents the interface to a target application and the kernel on the target PC. You use target objects to run and control the target application.

1-2

When you change a target object property on the host PC, information is exchanged with the target PC and the target application.

To create a target object,

1 Build a target application. The xPC Target software creates a target object

during the build process.

2 Use the target object constructor function xpc. In the MATLAB

window, type

Target objects are of class properties and methods specific to that object.

tg = xpctarget.xpc.

xpctarget.xpc. A target object has associated

Command

Scope Objects

In this section...

“What Is a Scope Object?” on page 1-3

“Scope Object Types” on page 1-4

What Is a Scope Object?

The xPC Target software uses scope objects to represent scopes on the target PC. Use scope object functions to view and co llect signal data.

See “Function Reference” and “Functions” for a reference of the scope functions.

Scope Objects

The xPC Target software uses scopes and scope objects as an alternative to using Simulink Simulink model system or outside a model system.

• A scope that is part of a Simulink model system is a scope block. You add

an xPC Target scope block to the model, build an application from that

model, and download that application to the target PC.

• A scope that is outside a model is not a scope block. For example, if you

create a scope with the

model system. You add this scope to the model after the model has been

downloaded and initialized.

This difference affects when and how the scope executes to acquire data.

Scope blocks inherit sample times. A scope block in the root model or a normal subsystem executes at the sample time of its input signals. A scope block in a conditionally executed (triggered/ enabled) subsystem executes whenever the containing subsystem executes. Note that in the latter case, the scope might acquire samples at irregular intervals.

Ascopethatisnotpartofamodelalwaysexecutesatthebasesampletime of the model. Thus, it might acquire repeated samples. F or example, if the model base sample time is 0.001, and you add to the scope a signal whose

scopes and external mode. A scope can exist as part of a

addscope method,thatscopeisnotpartofa

1-3

1 Target and Scope Objects

sample time is 0.005, the scope will acquire five identical samples for this signal,andthenthenextfiveidenticalsamples,andsoon.

Understanding the structure of scope objects will help you to use the MATLAB command-line interface to view and collect signal data.

Refer to Chapter 1, “Target and Scope Objects” for a description of how to use these objects, properties, and methods.

A scope object on the host PC represents a scope on the target PC. You use scope objects to observe the signals from your target application during a real-time run or analyze the data after the run is finished.

Tocreateascopeobject,

• Add an xPC Target scope block to your Simulink model, build the model to

create a scope, and then use the target object method

scope object.

getscope to create a

• Use the target object method

object, and assign the scope properties to the scope object.

A scope object has associated properties and methods specific to that object.

To read about scope object types, see “Scope Object Types” on page 1-4.

addscope to create a scope, create a scope

ScopeObjectTypes

You can create scopes of type target, host,orfile. Upon creation, The xPC Target software assigns the appropriate scope object data type for the scope type:

•

xpctarget.xpcsctg for scopes of type target

• xpctarget.xpcschost for scopes of type host

• xpctarget.xpcfs for scopes of type file

• xpctarget.xpcsc encompasses the object properties common to all the

scope object data types. The xPC Target software creates this object if you

create multiple scopes of different types for one model and combine those

scopes, for ex ample, into a scope vector.

1-4

Each scope object type has a group of object properties particular to that object type.

Scope Objects

1-5

1 Target and Scope Objects

The xpcsctg scope object of type target has the following object properties:

•

Grid

• Mode

• YLimit

The xpcschost scope object of type host has the following object properties:

•

Data

• Time

The xpcfs scope object of type file has the following object properties:

•

AutoRestart

• Filename

• Mode

1-6

• WriteSize

The xpcsc scope object has the following object properties. The other scope objects have these properties in common:

•

Application

• Decimation

• NumPrePostSamples

• NumSamples

• ScopeID

• Status

• TriggerLevel

• TriggerMode

• TriggerSample

• TriggerScope

• TriggerSignal

• TriggerSlope

• Type

Scope Objects

See the scope object function object properties.

get (scope object) for a description of these

1-7

1 Target and Scope Objects

1-8

Targets and Scopes in the MATLAB Interface

You can work with xPC Target target and scope objects through the MATLAB interface (MATLAB Command Window ), the target PC command line, a Web browser, or an xPC Target API. This chapter describes how to use the MATLAB interface to work with the target and scope objects in the following sections. See Chapter 8, “Using the Target PC Command-Line Interface” for a description of the target PC command-line interface.

• “Working with Target Objects” on page 2-2

• “Working with Scope Objects” on page 2-7

2 Ta r get s a n d S cop e s i n t he MATL AB

Interface

Working with Target Objects

In this section...

“Accessing Help for Target Objects” on page 2-2

“Creating Target Objects” on page 2-2

“Deleting Target Objects” on page 2-3

“Displaying Target Object Properties” on page 2-4

“Setting T arget Object Properties from the Host PC” on page 2-4

“Getting the Value of a Target Object Property” on page 2-5

“Using the Method Syntax with Target Objects” on page 2-6

Accessing Help for Target Objects

See “Function Reference” and “Functions” for a reference of the target object functions.

2-2

The target application object methods allow you to control a target application on the target PC from the host PC. You enter target application object methods in the M ATLA B window on the host PC or use MATLAB code scripts. To access the help for these methods, use the syntax

help xpctarget.xpc/method_name

If you want to control the target application from the target PC, use target PC commands. See Chapter 8, “Using the Target PC Command-Line Interface”.

Creating Target Objects

To create a target object,performthefollowing

1 Build a target application. the xPC Target software creates a target object

during the build process.

2 To create a single target object, or to create multiple target objects in your

system, u se the target object constructor function

as follows. For example, the following creates a target object connected

xpc (see xpctarget.xpc)

Working with Target Objects

to the host through an RS-232 connection. In the MATLAB Command

Window, type

tg = xpctarget.xpc('rs232', 'COM1', '115200')

The resulting target object is tg.

3 To check a connection between a host and a target, use the target function

targetping. For example,

tg.targetping

Note To ensure that you always know which target PC is associated with

your target object, you should always use this method to create target

objects.

4 To create a single target object, or to create the first of many targets in

your s ystem , use the target object constructor function

xpctarget.xpc as

follows. In the MATLAB Command Window, type

tg = xpctarget.xpc

The resulting target object is tg.

Note If you choose to use this syntax to create a target object, you should use the x PC Target software Explorer to configure your target PC. This ensures that command-line interactions know the correct target PC to work with.

Deleting Target Objects

To dele te a target object, use the target object destructor function delete .In the MATLAB window, type

tg.delete

If there are any scopes, file system, or FTP objects still associated with the target, this function removes all those scope objects as well.

2-3

2 Ta r get s a n d S cop e s i n t he MATL AB

Interface

Displaying Targ

You might want to application. Th execution time

After you buil you can list th target object

1 In the MATLAB

The current target application properties are uploaded to the host PC, and

MATLAB displays a list of the target object properties with the updated

values.

Note that the target object properties for

and

TETLog are not updated at this time.

2 Type

+tg

The Status property changes from stopped to running,andthelog

properties change to

e p roperties include the execution time and the average task

d a target application and target object from a Simulink model,

e target object properties. This procedure uses the default

name

et Object Properties

list the target object properties to monitor a target

tg as an example.

window, type

TimeLog, StateLog, OutputLog,

Acquiring.

2-4

For a list of target object properties with a description, see the target object function

get (target application object).

Setting Target Object Properties from the Host PC

You can change a target object property by using the xPC Target software set method or the dot notation on the host PC. (See “User Interaction” in the xPC Target Getting Started Guide guide for limitations on target property changes to sample times.)

With the xPC Target software you can use either a function syntax or an object property syntax to change the target object properties. The syntax

set(target_object, property_name,new_property_value) can be

replaced by

Working with Target Objects

target_object.property_name = new_property_value

For example, to change the stop time mode for the target object tg,

• In the MATLAB window, type

tg.stoptime = 1000

• Alternatively, you can type

set(tg, 'stoptime', 1000)

When you change a target object property, the new property value is downloaded to the target PC. The xPC Target kernel then receives the information and changes the behavior of the target application.

To get a list of the writable properties, type process a ssigns the default name of the target object to

set(target_object).Thebuild

tg.

Getting the Value of a Target Object Property

You can list a property value in the MATLAB window or assign that value to a MATLAB variable. With the xPC Target software you can use either a function syntax or an object property syntax.

The syntax

target_object.property_name

Forexample,toaccessthestoptime,

• In the MATLAB window, type

• Alternatively, you can type

To get a list of readable properties, type t arge t_object. Without assignment to a variable, the property values are listed in the MATLAB window.

get(target_object, property_name) can be replaced by

endrun = tg.stoptime

endrun = get(tg,'stoptime') or tg.get('stoptime')

2-5

2 Ta r get s a n d S cop e s i n t he MATL AB

Signals are not target object properties. To get the value of the Integrator1 signal from the model xpcosc,

• In the MATLAB window, type

outputvalue = getsignal ( tg,0)

where 0 is the signal index.

• Alternatively, you can type

tg.getsignal(0)

Note Method names are case sensitive. You must type the entire name. Property names are not case sensitive. You do not need to type the entire name as long as the characters you do type are unique for the property.

Interface

2-6

Using the Method Syntax with Target Objects

Use the method syntax to run a target object method. The syntax

method_name(target_object, argument_list) can be replaced with

target_object.method_name(argument_list)

Unlike properties, for which partial but unambiguous names are permitted, you must enter method names in full, and in lowercase. For example , to add a scope of type

• In the MATLAB window, type

tg.addscope('target',1)

• Alternatively, you can type

addscope(tg, 'target', 1)

target with a scope index of 1,

Working with Scope Objects

In this section...

“Accessing Help for Scope Objects” on page 2-7

“Displaying Scope Object Properties for a Single Scope” on page 2-7

“Displaying Sco pe Object Properties for All Scopes” on page 2-8

“Setting the Value of a Scope Property” on page 2-9

“Getting the Value of a Scope Property” on page 2-10

“Using the Method Syntax with Scope Objects” on page 2-11

“Acquiring Signal Data with Scopes of Type File” on page 2-11

“Acquiring Signal Data into Multiple, Dynamically Named Files with Scopes of Type File” on page 2-12

“Advanced Data Acquisition Topics” on page 2-14

Working with Scope Objects

Accessing Help for Scope Objects

See “Function Reference” and “Functions” for a reference of the scope object functions.

The scope object me tho ds allow you to control scopes on your target PC.

If you want to control the target application from the target PC, use target PC commands. See Chapter 8, “Using the Target PC Command-Line Interface”.

Displaying Scope Object Properties for a Single Scope

To list the properties of a single scope object, sc1,

1 In the MATLAB window, type

sc1 = getscope(tg,1) or sc1 = tg.getscope(1)

MATLAB creates the scope object sc1 from a previously created scope.

2 Type

2-7

2 Ta r get s a n d S cop e s i n t he MATL AB

sc1

The current scope properties are uploaded to the host PC, and then

MATLAB displays a list of the scope object properties with the updated

values. Because

sc1(1) or sc1([1]).

Note Only scopes with type ho st store data in the properties

scope_object.Time and scope_object.Data.

For a list of target object properties with a description, see the target function

get (target application object).

DisplayingScopeObjectPropertiesforAllScopes

To list the properties of all scope objects associated with the target object tg,

Interface

sc1 is a vector with a single element, you could also type

2-8

• In the MATLAB window, type

getscope(tg) or tg.getscope

MATLAB displays a list of all scope objects associated with the target

object.

• Alternatively, type

allscopes = getscope(tg)

allscopes = tg.getscope

The current scope properties are uploaded to the host PC, and then

MATLAB displays a list of all the scope object properties with the updated

values. To list some of the scopes, use the vector index. For example, to list

the first and third scopes, type

allscopes([1,3]).

For a list of target object properties with a description, see the target function

get (target application object).

Working with Scope Objects

Setting the Value of a Scope Property

With the xPC Target software you can use either a function syntax or an object property syntax. The syntax

new_property_value)

scope_object(index_vector).property_name = new_property_value

can be replaced by

Forexample,tochangethetriggermodeforthescopeobjectsc1,

• In the MATLAB window, type

sc1.triggermode = 'signal'

• Alternatively, you can type

set(sc1,'triggermode', 'signal')

set(scope_object, property_name,

sc1.set('triggermode', 'signal')

Note that you cannot u se dot notation to set vector object properties. To assign properties to a vector of scopes, use the you have a variable

sc12 for two scopes, 1 and 2.TosettheNumSamples

set method. For example, assume

property of the se scopes to 300,

1 In the MATLAB window, type

set(sc12,'NumSamples',300)

To get a list of the writable properties, type set(scope_object).

2-9

2 Ta r get s a n d S cop e s i n t he MATL AB

Getting the Value of a Scope Property

You can list a property value in the MATLAB window or assign that value to a MATLAB variable. With the xPC Target software you can use either a function syntax or an object property syntax.

Interface

The syntax

scope_object_vector(index_vector).property_name

get(scope_object_vector, property_name) can be replaced by

For exa mple, to assign the number of samples from the scope object sc1,

• In the MATLAB window, type

numsamples = sc1.NumSamples

• Alternatively, you can type

numsamples = get(sc1,'NumSamples')

sc1.get(NumSamples)

Note that you cannot use dot notation to get the v alues of vector object properties. To get properties of a vector of scopes, use the example, assume you have two scopes,

To get the value of

get(sc12,'NumSamples')

NumSamples for these scopes, in the MATLAB window, type

1 and 2, assigned to the variable sc12.

get method. For

2-10

You get a result like the following:

ans =

[300] [300]

To get a list of readable properties, type scope_ob ject. The property values are listed in the MATLAB window.

Working with Scope Objects

Using the Method Syntax with Scope Objects

Use the method syntax to run a scope object method. The syntax

method_name(scope_object_vector, argument_list) can be replaced

with either

•

scope_object.method_name(argument_list)

• scope_object_vector(index_vector).method_name(argument_list)

Unlike properties, for which partial but unambiguous names are permitted, enter method names in full, and in lowercase. For example, to add signals to the first scope in a vector of all scopes,

• In the MATLAB window, type

allscopes(1).addsignal([0,1])

• Alternatively, you can type

addsignal(allscopes(1), [0,1])

Acquiring Signal Data with Scopes of Type File

You can acqu ire signal data into a file on the target PC. To do so, you add a scope of type download it to the target PC, you can add a scope of type application.

For example, to add a scope of type to add signal

1 In the MATLAB window, type

sc=tg.addscope('file')

The xPC Target software creates a scope of type file for the application.

file to the application. After you build an application and

file to that

file named sc to the application, and

4 to that scope,

2-11

2 Ta r get s a n d S cop e s i n t he MATL AB

2 Type

sc.addsignal(4)

3 To start the scope, type

+sc

4 To start the target application, type

+tg

ThexPCTargetsoftwareaddssignal4tothescopeoftypefile. Whenyou start the scope and application, the scope saves the signal data for signal 4 to afile,bydefaultnamed

See “Scope of Type File” on page 3-50 in Chapter 3, “Signals and Parameters” for a description of scopes of type

If you want to acquire signal data into multiple files, see “Acquiring Signal Data into Multiple, Dynamically Named Files with Scopes of Type File” on page 2-12.

Interface

C:\data.dat.

file.

2-12

Acquiring Signal Data into Multiple, Dynamically Named Files with Scopes of Type File

You can acquire signal data into multiple, dynamically named files on the target PC. For example, you can acquiredataintomultiplefilestoexamine onefilewhilethescopecontinuestoacquire data into other files. To acquire data in multiple files, add a scope of type build an application and download it to the target PC, you can add a scope of type

file to that application. You can then con f ig ure that scope to log

signal data to multiple files.

For example, configure a scope of type the following characteristics:

• Logs signal data into up to nine files whose sizes do not exceed 4096 bytes.

• Creates files whose names contain the string

• Contains signal

file to the application. After you

file named sc to the application with

file_.dat.

Working with Scope Objects

1 In the MATLAB window, type

tg.StopTime=-1;

This parameter directs the target application to run indefinitely.

2 To add a scope of type file, type

sc=tg.addscope('file');

3 Toenablethefilescopetocreatemultiplelogfiles,type

sc.DynamicFileName='on';

Enable this setting to enable logging to multiple files.

4 To enable file scopes to collect d ata up to the number of samples, then

start over again, type

sc.AutoRestart='on';

Use this setting for the creation of multiple log files.

5 To limit each log file size to 4096,type

sc.MaxWriteFileSize=4096;

You must use this property. Set MaxWriteFileSize to a multiple of the

WriteSize property.

6 Toenablethefilescopetocreatemultiplelogfileswiththesamename

pattern, type

sc.Filename='file_<%>.dat';

This sequence directs the software to create up to nine log files, f ile_ 1.dat

to file_9.dat onthetargetPCfilesystem.

7 To add signal 4 to the file scope, type

sc.addsignal(4);

8 To start the scope, type

2-13

2 Ta r get s a n d S cop e s i n t he MATL AB

+sc

9 To start the target application, type

+tg

The software creates a log file named file_1.dat and writes data to

that file. When the size of

MaxWriteFileSize), the software closes the file and creates file_2.dat

for writing until its size reaches 4096 bytes. The software repeats this

sequence until it fills the last log file,

continues to run and collect data after

file_1.dat and continues to log data, overwriting the existing contents. It

cycles through the other log files sequentially. If you do not retrieve the

data from existing files before they are overwritten, the data is lost.

If you want to acquire signal data into a single file, see “Acquiring Signal Data with Scopes of Type File” on page 2-11.

Interface

file_1.dat reaches 4096 bytes (value of

file_9.dat. If the target application

file_9.dat, the software reopens

2-14

Advanced Data Acquisition Topics

The moment that an xPC Target scope begins to acquire data is user configurable. You can have xPC Target scopes acquire data right away, or define triggers for scopes such that the xPC Target scopes wait until they are triggered to acquire data. You can configure xPC Target scopes to start acquiring data when the following scope trigger conditions are met. These are known as trigger modes.

•

Freerun — Starts to acquire data as soon as the scope is started (default)

Software — Starts to acquire data in response to a user request. You

•

generate a user request when you call the scope method

scope function

Signal — Starts to acquire data when a particular signal has crossed a

•

xPCScSoftwareTrigger.

preset level

•

Scope — Starts to acquire data based on when another (triggering) scope

starts

trigger or the

Working with Scope Objects

You can use several properties to further refine when a scope acquires data. For example, if you set a scope to trigger on a signal (

Signal trigger mode),

youcanconfigurethescopetospecifythefollowing:

• The signal to trigger the scope (required)

• The trigger level that the signal must cross to trigger the scope to start

acquiring data

• Whether the scope should trigger on a rising signal, falling signal, or either

one

In the following topics, the trigger point is the sample during w hich the scope trigger condition is satisfied. For signal triggering, the trigger point is the sample during which the trigger signal passes through the trigger level. At the trigger point, the scope acquires the first sample. By default, scopes start acquiring data from the trigger point onwards. You can m od ify this behavior using the pre- and posttriggering.

• Pretriggering — Starts to acquire data N moments before a trigger occurs

• Posttriggering — Starts to acquire data N moments after a trigger occurs

The

NumPrePostSamples scope property controls the pre- and posttriggering

operation. This property specifies the number of samples to be collected before or after a trigger event.

• If

NumPrePostSamples is a negative number, the scope is in pretriggering

mode, where it starts collecting samples before the trigger event.

• If

NumPrePostSamples is a positive number, the scope is in a posttriggering

mode, where it starts collecting samples after the trigger event.

The following topics describe two examples of acquiring data:

• “TriggeringOneScopewithAnotherScopetoAcquireData”onpage2-16

— Describes a configuration of one scope to trigger another using the

concept of pre- and posttriggering

• “Acquiring Gap-Free Data Using Two Scopes” on page 2-18 — Describes

howtoapplytheconceptoftriggering one scope with another to acquire

gap-free data

2-15

2 Ta r get s a n d S cop e s i n t he MATL AB

Triggering One Scope with Another Scope to Acquire Data

This section describes the concept of triggering one scope with another to acquire data. The description uses actual scope objects and properties to describe triggers.

The ability to have one scope trigger another, and to delay retrieving data from the second after a trigger event o n the first, is most useful when data acquisition for the second scope is triggered after data acquisition for the first scope is complete. In the following explanation, Scope 2 is triggered by Scope 1.

• Assume two scopes objects are configured as a vector with the command

sc = tg.addscope('host', [1 2]);

• For Scope 1, set the following values:

- sc(1).ScopeI d = 1

- sc(1).NumSam ples = N

Interface

2-16

- sc1.NumPrePo stSa mples = P

• For Scope 2, set the following values:

- sc(2).ScopeI d = 2

- sc(2).Trigge rMod e = 'Scope'

- sc(2).Trigge rSco pe =1

- sc(2).Trigge rSam ple = range 0 to (N + P - 1)

In the figures below, TP is the trigger point or sample where a trigger event occurs. Scope 1 begins acquiring data as described.

In the simplest case, where

P=0, Scope 1 acquires data right away.

Working with Scope Objects

Pretriggering (P<0) on page 2-17 illustrates the behavior if P ,thevalueof

NumPrePostSamples, is negative. In this case, Scope 1 starts acquiring data |P| samples before TP. Scope 2 begins to acquire data only after TP occurs.

Pretriggering (P<0)

Posttriggering (P>0) on page 2-1 7 illustrates the behavior if P,thevalueof

NumPrePostSamples, is positive. In this case, Scope 1 starts acquiring data |P| samples after TP occurs.

Posttriggering (P>0)

2-17

2 Ta r get s a n d S cop e s i n t he MATL AB

Scope 1 triggers Scope 2 after the trigger event occurs. The following describes some of the ways you can trigger Scope 2:

•

sc(2).TriggerSample = 0 — Causes Scope 2 to be triggered when Scope 1

is triggered.

sc(2).TriggerSample = n > 0 —CausesTP for Scope 2 to be n samples

•

after

larger than

will never trigg er, since Scope 1 will never acquire more than

samples after TP.

sc(2).TriggerSample = 0 < n < (N + P) — E nables you to obtain

•

some of the functionality that is available with pre- or posttriggering. For

example, if you have the following Scope 1 and Scope 2 settings,

- Scope 1 has sc(1).NumPrePostSamples = 0 (no pre- or posttriggering)

- Scope 2 has sc(2).TriggerSam ple = 10

- Scope 2 has sc(2).NumPrePostSamp le = 0

Interface

TP forbothscopesasatthesamesample.

TP for Scope 1. Note that setting sc(2).TriggerSample to a value

(N+P-1)does not cause an error; it implies that Scope 2

(N + P -

2-18

The behavior displayed by Scope 2 is equivalent to having

sc(2).TriggerSample = 0 and sc(2).NumPrePostSamples = 10.

sc(2).TriggerSample = -1 — Causes Scope 2 to start acquiring data

•

fromthesampleafterScope1stopsacquiring.

Note The difference between setting TriggerSample = (N + P - 1), where

TriggerSample = -1 is that in the former case, the first sample of Scope 2

willbeatthesametimeasthelastsampleofScope1,whereasinthelatter, thefirstsampleofScope2willbeonesampleafterthelastsampleofScope1. This means that in the former case both scopes acquire simultaneously for one sample, and in the latter they will never simultaneously acquire.

N and P are the parameters of the triggering scope (Scope 1) and

Acquiring Gap-Free Data Using Two Scopes

With two s copes, you can acquire gap-free data. Gap-free data is data that two scopes acquire consecutively, with no overlap. The first scope acquires data up to N, then stops. The second scope begins to acquire data at N+1. This is functionality that you cannot achieve through pre- or posttriggering.

Working with Scope Objects

Acquisition of Gap-Free Data on page 2-1 9 graphically illustrates how scopes trigger one another. In this example, the set to

'Software'. This allows Scope 1 to be software triggered to acquire

data when it receives the command

TriggerMode property of Scope 1 is

sc1.trigger.

Acquisition of Gap-Free Data

The following procedure describes how you can programmatically acquire gap-free data with two scopes.

1 Ensure that you have already built and downloaded the Simulink model

xpcosc.mdl to the target PC.

2 In the MATLAB Command Window, assign tg to the target PC and set the

StopTime property to 1. For example,

tg=xpctarget.xpc tg.StopTime = 1;

3 Add two scopes of type host to the target application. You can assign the

twoscopestoavector,

sc, s o that you can work with both scopes with one

command.

2-19

2 Ta r get s a n d S cop e s i n t he MATL AB

sc = tg.addscope('host', [1 2]);

4 Add the signals of interest (0 and 1) to both scopes.

addsignal(sc,[0 1]);

5 Set the NumSamples property for both scopes to 500 and the Tri ggerSample

property for both scopes to -1. With this property setting, each scope

triggers the next scope at the end of its 500 sample acquisition.

set(sc, 'NumSamples', 500, 'TriggerSample', -1)

6 Set the TriggerMode property for both scopes to 'Scope'.Setthe

TriggerScope property such that each scopeistriggeredbytheother.

set(sc, 'TriggerMode', 'Scope'); sc(1).TriggerScope = 2; sc(2).TriggerScope = 1;

7 Set up storage for time, t,andsignal,data acquisition.

Interface

2-20

t=[]; data = zeros(0, 2);

8 Start both scopes and the model.

start(sc); start(tg);

Note that both scopes receive exactly the same signals, 0 and 1.

9 Trigger scope 1 to start acquiring data.

scNum = 1; sc(scNum).trigger;

Setting scNum to 1 indicates that scope 1 will acquire data first.

10 Start acquiring data using the two scopes to double buffer the data.

while (1)

% Wait until this scope has finished acquiring 50 % or the model stops (scope is interrupted).

0 samples

while ~(strcmp(sc(scNum).Status, 'Finished') || ...

strcmp(sc(scNum).Status, 'Interrupted')), end % Stop buffering data w hen the model stops. if strcmp(tg.Status, 'stopped')

break end % Save the data. t( end + 1 : end + 500) = sc(scNum). Time ; data(end + 1 : end + 500, :) = sc(scNum).Data; % Restart this scope. start(sc(scNum)); % Switch to the next scope.

%Shortcut for if(scNum==1) scNum=2;else scNum=1,end scNum = 3 - scNum; end

11 When done, remove the scopes.

% Remove the scopes we added. remscope(tg,[1 2]);

Working with Scope Objects

The following is a complete code listing for the preceding double-buffering data acquisition p rocedure. You can copy and paste this code into a MATLAB file and run it after you download the model (

xpcosc.mdl) to the target PC. This

example assumes that the communication speed between the host and target PC is fast enough to handle the number of samples and can acquire the full data set before the next acquisition cycles starts. In a similar way, you can use more than two scopes to implement a triple- or quadruple-buffering scheme.

% Assumes model xpcosc .mdl has been built and loaded on the target PC.

% Attach to the target PC and set StopTime to 1 sec.

tg = xpctarget.xpc;

tg.StopTime = 1;

% Add two host scopes.

sc = tg.addscope('host', [1 2]);

% [0 1] are the signals of interest. Add to both scopes.

addsignal(sc,[0 1]);

% Each scope triggers next scope at end of a 500 sample acquisition.

set(sc, 'NumSamples', 500, 'TriggerSample', -1);

set(sc, 'TriggerMode', 'Scope');

sc(1).TriggerScope = 2;

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2 Ta r get s a n d S cop e s i n t he MATL AB

sc(2).TriggerScope = 1;

% Initialize time and data log.

t = [];

data = zeros(0, 2);

% Start the scopes and the model.

start(sc);

start(tg);

% Start things off by triggering scope 1.

scNum = 1;

sc(scNum).trigger;

% Use the two scopes as a double buffer to log the data.

while (1)

% Wait until this scope has finished acquiring 500 samples

% or the model stops (scope is interrupted).

while ~(strcmp(sc(scNum).Status, 'Finished') || ...

% Stop buffering data when the model stops.

if strcmp(tg.Status, 'stopped')

break

end

% Save the data.

t( end + 1 : end + 500) = sc(scNum).Time;

data(end + 1 : end + 500, :) = sc(scNum).Data;

% Restart this scope.

start(sc(scNum));

% Switch to the next scope.

scNum=3-scNum;

end

% Remove the scopes we added.

remscope(tg,[1 2]);

% Plot the data.

plot(t,data); grid on; legend('Signal 0','Signal 1');

Interface

strcmp(sc(scNum).Status, 'Interrupted')), end

2-22

Signals and Parameters

Changing parameters in your target application while it is running in real time, and checking the results by viewing signal data, are two important prototyping tasks. The xPC Target software includes command-line and graphical user interfaces to complete these tasks. This chapter includes the following sections:

• “Monitoring Signals” on page 3-2

• “Signal Tracing” on page 3-15

• “Signal Logging” on page 3-56

• “Parameter Tuning and Inlining Parameters” on page 3-65

• “Nonobservable Signals and Parameters” on page 3-85

3 Signals and Parameters

Monitoring Signals

In this section...

“Introduction” on page 3-2

“Signal Monitoring with xPC Target Explo rer” on page 3-2

“Signal Monitoring with the MATLAB Interface” on page 3-9

“Monitoring Stateflow States” on page 3-10

Introduction

Signal monitoring is the process for acquiring signal data during a real-time run w ithout time information. The advantage with signal monitoring is that there is no additional load on the real-time tasks. Use signal m onito ring to acquire signal data without creating scopes that run on the target PC.

In addition to signal monitoring, the xPC Target software enables you to monitor Stateflow and MATLAB command-line interfaces. You designate data or a state in a Stateflow diagram as a test point. This makes it observable during execution. See the Stateflow and Stateflow can work with Stateflow states as you do with xPC Target signals, such as monitoring or plotting Stateflow states.

After you start running a target application, you can use signal monitoring to get signal data.

Note xPC Target Explorer works with multidimensional signals in column-major format.

states as test points through the xPC Target Explorer

Coder™ User’s Guide for details. You

Signal Monitoring with xPC Target Explorer

This procedure uses the model xpcosc.mdl as an example, and assumes you created and downloaded the target application to the target PC. For meaningful values, the target application should be running.

3-2

Monitoring Signals

1 If xPC Target Explorer is not started, start it now. In xPC Target

Explorer, select the node of the running target application in which you are interested, for example,

xpcosc.

The target PC Target Application Properties pane a ppears.

2 In the Solver pane, change the Stop time parameter to inf (infinity).

Click Apply.

3 To get the list of signals in the target application, expand the target

application node, then expand the

Model Hierarchy node under the target

application node.

3-3

3 Signals and Parameters

The model hierarchy expands to show the Simulink objects (signals and parameters) in the Simulink model.

3-4

The Model Hierarchy node can have the following types of nodes:

Monitoring Signals

Icons

Nodes

Subsystems, including their signals and parameter

Referenced models, including their signals set as test points

Parameters

Signals

Stateflow states set as test points

Only xPC Target tunable parameters and signals of the application, as represented in the Simulink model, appear in the

Model Hierarchy node.

Note This example currently has only parameters and signals. If a block has a name that consists of only spaces, xPC Target Explorer does not display a node for that block. To monitor a signal from that block, provide an alphanumeric name for that block and rebuild and download that block.

If you make changes (such as adding an xPC Target scope) to the model associated with the downloaded application, then rebuild that model and download it again to the target PC, you should reconnect to the target PC to refresh the

Model Hierarchy node.

4 To vie

signa

a Open t

b Righ

the o

c Buil

d Whe

the Thi yo

w only labeled signals (the xPC Target software refers to Simulink

l names as signal labels) :

xpcosc.mdl file.

t-click a signal line and name that signal. For example, right-click

utput of the Signal Generator block and name it

SignalG.

d and download the updated model.

n the updated model is displayed in xPC Target Explorer, right-click

Model Hierarchy node and select View Only Labeled Signals.

s command assumes that you have labeled one or more signals in

ur model.

3-5

3 Signals and Parameters

e Re-expand the Model Hierarchy no de to see the labeled sign al s .

To view the blo ck path for a labeled signa l, hover over the l abeled signal. For example,

3-6

To display all the model signals again, right-click the Model Hierarchy node and select View All Signals. You can still view the signal label by hovering over the labeled signal. For example,

Note When working with si gn a l labels:

Monitoring Signals

• Signal labels must be unique.

• xPC Target software ignores signal labels in referenced models.

f Return to the model, remove the signal name y ou added, and rebuild and

download the target application. The remaining examples in this section assume that you do not have any labelled signals in your model.

5 To go to the corresponding Simulink model subsystem, right-click the

application node and select Go to Simulink

6 To get the value of a signal, select the signal in the Model Hierarchy node.

subsystem or block.

3-7

3 Signals and Parameters

The value of the signal is shown in the right pane.

3-8

7 Right-click the target application and select Start.

The application starts running.

8 To change the numeric format display of the signal, right-click the Model

Hierarchy

The D isplay Format String dialog box is displayed.

node and select Edit Signals F ormat String.

Monitoring Signals

9 Enter the signal format. Use one of the following. By default, the format is

%0.25g.

Type Descri ption

%e or %E

Exponential format using e or E

Floating point

Signed value printed in f or e format depending on which is smaller

Signed value printed in f or E format depending on which is smaller

Monitoring Signals from Referenced Models

You can monitor signals from referenced models the same way that you do any o the r signal, with the exception that you must set the test point for the signal in the referenced model before you can monitor it. Additionally, the software ignores signal labels in referenced models.

Signal Monitoring with the MATLAB Interface

This procedure uses the model xpc_osc3.mdl as an example, and assumes you created and downloaded the target application to the target PC. It also assumes that you have assigned

1 To get a list of signals, type either

set(tg, 'ShowSignals', 'On')

tg.ShowSignals='On'

tg to the appropriate target PC.

3-9

3 Signals and Parameters

ThelattercommandcausestheMATLABwindowtodisplayalistofthe target object properties for the available signals. For example, the signals for the model

xpc_osc3.mdl are shown below. Note that the Label column

is em pty because there are no labelled signals in the model. If your signal has a unique label, its label is displayed in this column. If the label is not unique, the command returns an error. If the signal label is in a referenced model, the software ignores it.

ShowSignals = on

Signals = INDEX VALUE BLOCK NAME LABEL

0 0.000000 Signal Generator 1 0.000000 Transfer Fcn

2 To get the value of a signal, use the getsignal method. In the MATLAB

Command Window, type

tg.getsignal(0)

where 0 is the signal index. the MATLAB interface displays the value of signal

3-10

ans=

3.731

Note The xPC Target software lists referenced model signals with their full block path. For example,

xpc_osc5/childmodel/gain.

See also “Signal Tracing with the MATLAB Interface” on page 3-39.

Monitoring Stateflow States

This procedure uses the model old_sf_car.mdl as an example. It describes one way to set Stateflow states as test points for monitoring.

1 In the MATLAB window, type

old_sf_car

2 In the Simulink window, click Simulation > Configuration Parameters.

Monitoring Signals

The Configuration Parameters dialog box is displayed for the model.

3 Click the Real-Time Workshop node.

The Real-Time Workshop pane opens.

4 To build a basic target application, in the Target selection section, click

the Browse button at the System targ et file list. Click

xpctarget.tlc,

then click OK.

5 As necessary, you can click the xPC Target options node and continue to

make changes.

6 When you are done, click OK.

3-11

3 Signals and Parameters

7 In the old_sf_car model, double-click the shift_logic chart.

The

shift_logic chart is displayed .

3-12

8 In the chart, click Tools > Explore.

The Model Explorer is displayed.

9 In the Model Explorer, expand old_sf_car.

10 Expand shift_logic.

11 Expand gear_state, then select first.

12 In the rightmost pane, State first, select the Test point check box. This

creates a test point for the

first state.

Monitoring Signals

13 Click Apply.

14 Build and download the old_sf _car target application to the target PC.

You can now view the states wi th xPC Target Explorer or the MATLAB interface.

Monitoring Stateflow States with xPC Target Explorer

This topic assumes that you have already set Stateflow states as test points (see “Monitoring Stateflow States” on page 3-10 if you have not).

1 If the xPC Target Explorer is not yet started, start it now and connect it to

thetargetPCthathasthedownloaded

2 To view the test point in the xPC Target Explore r, expand the

Model Hierarchy node and navigate to shift_logic.Thetestpoint gear_state.first appears like any other signal in the hierarchy, as

follows:

old_sf_car target application.

3 Choose the state as you do a signal to monitor.

3-13

3 Signals and Parameters

Monitoring Stateflow States with the MATLAB Interface

This topic assumes that you have already set Stateflow states as test points (see “Monitoring Stateflow States” on page 3-10 if you have not).

1 To get a list of signals in the MATLAB Command Window , type

tg=xpc

2 To display the signals in the target application, type either

set(tg, 'ShowSignals', 'On'); tg

tg.ShowSignals='On'

The latter causes the MATLAB window to display a list of the target object properties for the available signals.

3-14

For Stateflow states that you have set as test points, the state appears in the point for the

old_sf_car model, the state of interest is first. This state appears as

BLOCK NAME column like any signal. For example, if you set a test

first state of gear_state in the shift_logic chart of the

follows in the list of signals in the MATLAB interface:

shift_logic:gear_state.first

shift_logic

isthepathtotheStateflowchartandgear_state.first is

thepathtothespecificstate.

Signal Tracing

In this section...

“Introduction” on page 3-15

“Signal Tracing with xPC Target Explorer” on page 3-15

“Signal Tracing with the MATLAB Interface” on page 3-39

“Signal Tracing with xPC Target Scope Blocks” on page 3-48

“Signal Tracing with Simulink External Mode” on page 3-50

“Signal Tracing with a Web Browser” on page 3-54

Introduction

Signal tracing is the process of acquiring and visualizing signals while running a target application. In its most basic sense, allows you to acquire signal data and visualize it on the target PC or upload the signal data and visualize it on the host PC while the target application is running.

Signal Tracing

Signal tracing differs from signal logging. Wi th signal logging you can only look at signals after a run is finished and the log of the entire run is available. For i nfo r m ation on signal logging, see “Signal Logging” on page 3-56.

Note xPC Target Explorer works with multidimensional signals in column-major format.

Signal Tracing with xPC Target Explorer

The procedures in this topic use the model xpcosc.mdl as an example, and assume you have created, downloaded, and started the target application on the target PC.

• “Creating Scopes” on page 3-16

• “Adding Signals to Scopes” on page 3-23

• “Stopping Scopes” on page 3-27

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3 Signals and Parameters

• “Software Triggering Scopes” on page 3-28

• “Configuring the Host Scope Viewer” on page 3-30

• “Acquiring Signal Data into Multiple, Dynamically Named Files on the

Target PC” on page 3-30

• “Copying Files to the Host PC” on page 3-34

• “Exporting Data from File Scopes to MATLAB Workspace” on page 3-35

• “Saving and Reloading xPC Target Application Sessions” on page 3-37

• “Deleting Files from the Target PC” on page 3-39

You can add or remove signals from target or host scopes while the scope is either stopped or running. For file scopes, you must stop the scope first before adding or removing signals.

Creating Scopes

1 In xPC Target Explorer, ensure that your xpcosc application is still

running.

3-16

2 To get the list of signals in the target application, expand the Model

Hierarchy

node under the target application.

Signal Tracing

The model hierarchy expands to show the elements in the Simulink model.

3 To get the list of scope types yo u can have in the target app lica tion, expand

the

xPC Scopes node below the application node.

The

xPC Scopes node expands to show the possible scope types a target

application can have.

3-17

3 Signals and Parameters

3-18

4 TocreateascopetodisplayonthetargetPC,right-clicktheTarget Scopes

node under the xPC Scopes node.

A context menu appears. This lists the actions you can perform on target PC scopes. For example, within the current context, you can create a target PC scope.

5 Select Add Target Scope.

pe node appears under

Asco

pe is labeled

sco

Scope 1.

Target Scopes. In this example, the new

Signal Tracing

You can add oth can add as many PC resources c

6 To create a scope to be displayed on the host PC, right-click the Host

Scopes

node under the xPC Scopes node.

er scopes, including those of type

file and host scopes as you want. as long as your target

an support them.

host and file.Note,you

A context menu appears. This lists the actions you can perform on host PC scopes. For example, within the curre nt context, you can create a host PC scope.

7 Select Add Host Scope.

A scope node appears under is labeled as

8 To visualize the host scope on the host PC, right-click Host Scopes from

the

xPC Scopes node.

Scope 2.

Host Scopes. In this example, the new scope

A drop-down list appears.

3-19

3 Signals and Parameters

9 Select View Scopes.

The xPC Target Host Scope Viewer window appears. Note that the signals you add to the scope will appear at the top right of the viewer.

3-20

10 To list the properties of the scope object Scope 2, click the xPC Target

Explorer tab to return to that window, and left-click you can configure the docking view using the MATLAB docking feature.)

The scope properties are shown in the rightmost pane.

Scope 2. (Note that

Signal Tracing

11 To create a scope to acquire signal data into a file on the target PC file

system, right-click the

File Scopes node under the xPC Scopes node.

Select Add File Scope.

A scope node appears under is labeled

Scope 3.

File Scopes. In this example, the new scope

By default, the software creates a file in the target PC C:\ folder. The nameofthefiletypicallyconsistsofthescopeobjectname,

ScopeId,and

the beginning letters of the first signal added to the scope.

3-21

3 Signals and Parameters

12 If you want to specify a different folder or filename, select the scope.

The scope property pane is displayed. In the File name field, enter the full pathname for the file. Note that the current folder for the target PC appears at the to p of the pane.

3-22

Signal Tracing

Your next task is to add signals to the scopes. The following procedure assumes that you have added scopes to the target PC and host PC.

Adding Signals to Scopes

This topic describes how to add signals using the xPC Target Explorer Add to Scopes command. If a scope does not exist, you can drag a signal to a

Host Scope, Target Scope, or File Scope icon to create a scope of that type in xPC Target Explorer.

1 In the xPC Target Explorer window, add signals to the target PC scope,

Scope 1. For example, to add signals Integrator1 and Signal Generator,

right-click each signal and select Add to Scopes.FromtheAdd to Scopes list, select

scopetoaddthesignaltothatscope.)

The

Scope 1 node is shown with a plus sign.

Scope 1. (Note that you can also drag the signal to the

2 Expand the Scope 1 node.

Scope 1 signals are displayed.

The

If one of the signals has been labeled. you can hover over the signal to display the signal la bel. For example,

3-23

3 Signals and Parameters

3 Start the scop

Start.

e. For example, to start

Scope 1, right-click it and select

3-24

Signal Tracing

The target screen plots the signals after collecting each data package. During this time, you can observe the behavior of the signals while the scope is running.

4 Add si

5 Expand the Scope 2 node.

gnals to the host PC scope. For example, to add signals and Si From t asign

The

gnal Generator

he Add to Scopes list, select

al from one scope to another to add that signal to another scope.)

Scope 2 node is shown with a plus sign.

Scope 2 signals are displayed.

, right-click each signal and select Add to Scopes.

Integrator1

Scope 2. (Note that you can also drag

3-25

3 Signals and Parameters

6 Start the scope. For example, to start the scope Sco pe 2, right-click Scope

2 in the

The xPC Target Host Scope V i ew e r window plots the signals after collecting each data package. During this time, you can observe the behavior of the signals while the scope is running.

Host Scopes node of the xPC Target Explorer and select Start.

3-26

Signal Tracing

7 Add signals to the scope of type file. For example, to add signals

Integrator1 and Signal Generator, right-click each signal and select

Add to Scopes.FromtheAdd to Scopes list, select

Scope 3. (Note that

you can also drag a signal from one scope to another to add that signal to another scope.)

The

Scope 3 node is shown with a plus sign.

8 Expand the Scope 3 node.

Scope 3 signals are displayed.

The

9 To specify a filename for the data file, select the scope of type file.In

the right pane, enter a name in the Filename parameter. While in the parameter field, press Enter to save the filename.

Note that there is no name initially assigned. If you do not s pecify a filename, then after you start the scope, the software assigns a name for thetargetPCfiletoacquirethesignaldata. Thisnametypicallyconsists of the scope object name,

ScopeId, and the beginning letters of the first

signal added to the scope.

10 Start the scope. For example, to start the scope Scope 3, right-click Scope

3 in the

File Scopes node of the xPC Target Explorer and select Start.

For file scopes, the xPC Target software saves data to a file on the target PC flash disk.

Your next task is to stop the scopes. The following procedure assumes that you have started scopes.

Stopping Scopes

1 Stopthescopes. Forexample,tostopScope 1, right-click it and select

Stop.

3-27

3 Signals and Parameters

The signals shown on the target PC stop updating while the target application continues running, and the target PC displays the following message:

Scope: 1, set to state 'interrupted'

2 Stop the target application. For example, to stop the target application

xpcosc, right-click xpcosc and select Stop.

The target application on the target PC stops running, and the target PC displays the following messages:

minimal TET: 0.0000006 at time 0.001250 maximal TET: 0.0000013 at time 75.405 500

Note that if you stop the target application before stopping the scope, the scope stops, too.

Ifyouhavefilescopes,youcancopythefilethatcontainsthesignaldatafrom the target PC to the host PC. See “Copying Files to the Host PC” on page 3-34.

3-28

Software Triggering Scopes

You can set up a scope such that only a user can trigger the scope. This section assumes that you have added a scope to your target application (see “Creating Scopes” on page 3-16) and that you have added signals to that scope (see “Adding Signals to Scopes” on page 3-23).

1 In the xPC Target Explorer window, select the scope that you want to

trigger by software. For example, select

The properties pane for that scope is displayed.

Scope 1.

2 From the Trigger mode list, select Software.ClickApply.

Signal Tracing

3 Start the scope and target application.

4 Obse

5 Right-click the scope to be triggered. For example, select Scope 1.

6 Select Trigger.

7 Obs

rvethatthescopehasnoplotteddata.

erve that the scope now has plotted data.

3-29

3 Signals and Parameters

Configuring the Host Scope Viewer

You can customize your host sco pe viewer. This section assumes that you have added a host scope to your target application, started the host scope viewer, and added signals “Creating S co pe s” on page 3-16 and “Adding Signals to Scopes” on page 3-23). These viewer settings are per scope.

In the xPC Target Host Scope Viewer, right-click anywhere in the axis area of the viewer.

A context menu is displayed. This context menu contains options for the following:

•

View Mode —SelectGraphical for a graphical display of the data. Select Numerical for a numeric representation of the data.

Legends — Select and desele ct this option to toggle the display of the

•

signals legend in the top right of the viewer.

•

Grid — Select and deselect this option to toggle the display of grid lines in

the viewer.

Integrator1 and Signal Generator (see

3-30

•

Y-Axis — Enter the desired values. In the Enter Y maximum limit and

Enter Y minimum limit text boxes, enter the range for the y-axis in the

Scope window.

•

Export — Select the data to export. Select Export Variable Names

to export scope data names. In the Data Variable Name and Time Variable Name text boxes, enter the names of the MATLAB variables to

save data from a trace. Click the OK button. The default name for the data variable is variable is Select Export Scope Data to export scope data to the MATLAB interface.

application_name_scn_data, and the default name for the time

application_name_scn_time where n is the scope number.

Acquiring Signal Data into Multiple, Dynamically Named Files on the Target PC

You can acquire signal data into multiple, dynamically named files on the target PC. For example, you can acquiredataintomultiplefilestoexamine onefilewhilethescopecontinuestoacquire data into other files. To acquire data in multip l e files, add a scope of type file to the a pplication. After you build an application and download it to the target PC, you can add a scope

Signal Tracing

of type file to that application. You can then configure that scope to log signal data to multiple files. This section assumes that you have added a scopetoyourtargetapplication(see“CreatingScopes”onpage3-16). Italso assumes that you have added signals to that scope (see “Adding Signals to Scopes” on page 3-23).

1 In xPC Targe t Explorer, expand the target PC node associated with the

target PC file system you want to access. For example, expand

2 Under TargetPC1, expand the target application node and navigate to the

File Scope(s) node.

3 Right-click this node and add a file scope.

4 Add one or more scopes to that file scope. For example, add Integrator1

TargetPC1.

and Signal Generator to the scope.

5 Right-click the scope you just added (for example, Scope:1). The scope

property pane for this scope is displa yed.

3-31

3 Signals and Parameters

3-32

6 To en

ablethefilescopetocreatemultiplelogfileswiththesamename

ern, in the File name box, enter a nam e like

patt

This sequence directs the software to create up to nine log files, to file_9.dat, on the target PC file system.

file_<%>.dat.

file_1.dat

7 Select the Enable auto restart check box. The Enable file auto

increment check box is enabled.

8 Select the Enable file auto increment check box.

9 In the Max file size box,enteravaluetolimitthesizeofthesignallog

files. For example, to limit each log file s ize to 4096 bytes, enter

4096.

This value must be a multiple of the Write size value.

10 Click A pply. Thesavedvaluesappearasfollows:

Signal Tracing

11 Right-click the new file scope and select Start.

12 Start the associated target application.

The software creates a log file named file. When the size of

file_1.dat reaches 4096 bytes (value of Max file

size), the software closes the file. It then creates

file_1.dat and writes data to that

file_2.dat for writing

until its size reaches 40 96 b ytes. The software repeats this s eq uence until it fills the last log file, and collect data after

file_9.dat. If the target application continues to run

file_9.dat, the software reopens file_1.dat and

continues to log data, overwriting the existing contents. It cycles through the other log files sequentially.

3-33

3 Signals and Parameters

You can enable the creation of up to 99999999 files (<%%%%%%%%>.dat). The length of a file name, including the specifier, cannot exceed eight characters. See the Filename descriptioninthe

get (target application object) for

a details about this specif ier.

Copying Files to the Host PC

From xPC Target Explorer, you can download target PC files from the target PC to the host PC.

1 In xPC Targe t Explorer, expand the target PC node associated with the

target PC file system you want to access. For example, expand

2 Under TargetPC1,expandtheFile System node.

Nodes representing the drives on the target PC are displayed.

TargetPC1.

3-34

3 Expandthenodeofthedrivethatcontainsthefileyouwant.Forexample,

local disk: c:\.

4 Select the fold er that contains the file you want. For example, select the

node labeled

local disk: c: \.

The contents of that folder are displayed in the right pane.

5 In the right pane, right-click the file you want to copy to the host PC. For

example, right-click

SC3SIGNA.DAT.

A context-sensitive menu is displayed.

6 Select Save to Host PC .

Signal Tracing

A browser dialog box is displayed.

7 Choose the folder to contain the signal data file. If you want, you can also

save the file under a different name or create a new folder for the file.

xPC Target Explorer copies the contents of the selected file,

SC1INTEG.DAT

for example, to t h e selected folder.

You can examine the contents of the signal data file. See “Retrieving a File fromtheTargetPCtotheHostPC”onpage9-7inChapter9,“Workingwith Target PC Files and File Systems”.

Exporting Data from File Scopes to MATLAB Workspace

From xPC Target Explorer, you can export data from target PC files from the target PC to the MATLAB workspace. This topic assumes that you have

3-35

3 Signals and Parameters

created a scope of type file that contains signal data (see “Adding Signals to Scopes” on page 3-23).

1 In xPC Targe t Explorer, expand the target PC node associated with the

target PC file system you want to access. For example, expand

2 Under TargetPC1, find the target application and ensure that it is not

TargetPC1.

running.

3 Under TargetPC1,expandthexPC Scopes node.

All the scopes you have added are displayed.

4 Right-clickonthescopeoftypefileforwhichyouwanttoexportthesignal

data and select Export to workspace.

3-36

The Export to workspace dialog box is displayed.

5 Enter a variable name for the workspace data. For example, enter

sig_integ.ClickOK.

he M ATLAB desktop, the Workspace pane displays the new variable

In t

nam

Signal Tracing

You can examine and otherwise manipulate the data. You can also plot the data with

plot(sig_integ.data). This is an alternate method to “Retrieving

the Contents of a File from the TargetPCtotheHostPC”onpage9-11in Chapter 9, “Working with Target PC Files and File Systems”.

Saving and R

eloading xPC Target Application Sessions

Once you have a set of application configurations, you can save the xPC Target application session, including scope and target PC settings, to a standard MATLAB MAT-file on the host PC. You can then later reload this saved session to another xPC Target application session. This feature lets you save and restore xPC Target application sessions so that you do not have to reconfigure target PC and target application settings each time you start xPC Target Explorer.

To save a sessio n,

1 Ensure that xPC Target Explo rer is connected to a target PC.

2 In xPC T

3 In xPC Target Explorer, right-click the target PC you are interested in and

arget Explorer, load a target application on the target PC.

select Save Session. For example,

3-37

3 Signals and Parameters

A Save Targ

4 As necessary, browse to the desired folderandenterauniquename. For

example,

et Session as dialog box i s displayed.

xpcsession1.mat.

To restore a s ession,

1 Ensure that xPC Target Explo rer is connected to a target PC.

2 In xPC Target Explorer, load a target application on the target PC. This

target application must be the same target applic ati on for which the session was saved.

3 In xPC

selec

Target Explorer, right-click the target PC you are interested in and

t Load Session. For example,

3-38

Signal Tracing

A Load Target Session as dialog box is displayed.

4 As necessary, browse to the desired folder and select the session you are

interested in. For example,

xpcsession1.mat.

Adialog new sess

5 Click Yes.

xPC Target Explorer loads the saved settings.

Delet

From xPC Target Explorer on the host PC, you can d elete the scope data fileonthetargetPCfilesystem. Usethesameprocedureasdescribedin “Copying Files to the Host PC” on page 3-34, but select Delete instead of Save to Host PC. xPC Target Explorer removes the selected file from the target PC file system.

box is displayed asking you to confirm that you want to load a ion.

ing Files from the Target PC

Signal Tracing with the MATLAB Interface

Creating a scope object allows you to select and view signals using the scope methods. This section describes how to trace signals using xPC Target

3-39

3 Signals and Parameters

functions instead of using the xPC Target graphical user interface. This procedure assumes that you have assigned

tg to the appropriate target PC.

After you create and download the target application, you can view output signals.

Using the MATLAB interface, you can trace signals with

• Host or target scopes (see “Signal Tracing with the MATLAB Interface and

Target Scopes” on page 3-40 for a description of with target scopes)

• File scopes (see “Signal Tracing with the MATLAB Interface and File

Scopes” on page 3-44)

You must stop the scope before adding or removing signals from the scope.

Signal Tracing with the MATLAB Interface and Target Scopes

This procedure uses the Simulink model xpcosc.mdl as an example, and assumes you have built the target application for this model. It describes how to trace signals with target scopes.

3-40

1 Start running your target application. Type any of

+tg

tg.start

start(tg)

The target PC displays the following message.

System: execution started (sample tim e: 0.0000250)

2 To get a list of signals, type either

set(tg, 'ShowSignals', 'on')

Signal Tracing

tg.ShowSignals='on'

The MATLAB window displays a list of the target object properties for the a vailable signals. For example, the signals for the model

xpcosc.mdl

are as follows:

ShowSignals = on

Signals = INDEX VALUE BLOCK NAME LABEL

0 0.000000 Integrator1 1 0.000000 Signal Generator 2 0.000000 Gain 3 0.000000 Integrator 4 0.000000 Gain1 5 0.000000 Gain2 6 0.000000 Sum

For more information, see “Signal Monitoring with the MATLAB Interface” on page 3-9.

3 Create a scope to be displayed on the target PC . For example, to create a

scope with an identifier of

1 and a scope object name of sc1,type

sc1=tg.addscope('target', 1)

sc1=addscope(tg, 'target', 1)

4 List the properties of the scope object. For example, to l ist the properties of

the scope object

sc1

sc1,type

The MATLAB window displays a list of the scope object properties. Notice that the scope properties of type

target.

xPC Scope Object

Application = xpcosc ScopeId = 1 Status = Interrupted Type = Target

Time and Data are not accessible with a scope

3-41

3 Signals and Parameters

NumSamples = 250 NumPrePostSamples = 0 Decimation = 1 TriggerMode = FreeRun TriggerSignal = -1 TriggerLevel = 0.000000 TriggerSlope = Either TriggerScope = 1 TriggerSample = -1 Mode = Redraw (Graphical) YLimit = Auto Grid = On Signals = no Signals defined

5 Add signals to the scope object. For example, to add Integrator1 and

Signal Generator,type

sc1.addsignal ([0,1])

3-42

addsignal(sc1,[0,1])

The target PC displays the following messages.

Scope: 1, signal 0 added Scope: 1, signal 1 added

After you add signals to a scope object, the signals are not shown on the target screen until you start the scope.

6 Start the scope. For example, to start the scope sc1,typeeither

+sc1

sc1.start

start(sc1)

The target screen plots the signals after collecting each data package. During this time, you can observe the behavior of the signals while the scope is running.

7 Stop the scope. Type either

-sc1

sc1.stop

stop(sc1)

The signals shown on the target PC stop updating while the target application continues running, and the target PC displays the following message.

Signal Tracing

Scope: 1, set to state 'interrupted'

8 Stop the target application. In the MATLAB window, type either

-tg

tg.stop

stop(tg)

The target application on the target PC stops running, and the target PC displays the following messages.

minimal TET: 0.000023 at time 1313.7 8900 0 maximal TET: 0.000034 at t ime 407.956000

3-43

3 Signals and Parameters

Signal Tracing with the MATLAB Interface and File Scopes

This procedure uses the Simulink model xpcosc.mdl as an example, and assumes you have built the target application for this model. It also assumes that you have a serial communication connection. Thistopicdescribeshowto trace signals w ith file scopes .

Note The signal data file can quickly increase in size. You should examine thefilesizebetweenrunstogaugethegrowthrateofthefile.Ifthesignal data file grows beyond the available space on the disk, the signal data might be corrupted.

1 Create an xPC Target application that works with file scopes. Type

tg=xpctarget.xpc('rs232', 'COM1', '115200')

2 To get a list of signals, type either

set(tg, 'ShowSignals', 'on')

3-44

tg.ShowSignals='on'

The MATLAB window displays a list of the target object properties for the a vailable signals. For example, the signals for the model

xpcosc.mdl

are shown below.

ShowSignals = on

Signals = INDEX VALUE BLOCK NAM E LABEL

0 0.000000 Integrator1 1 0.000000 Signal Generator 2 0.000000 Gain 3 0.000000 Integrator 4 0.000000 Gain1 5 0.000000 Gain2 6 0.000000 Sum

For more information, see “Signal Monitoring with the MATLAB Interface” on page 3-9.

Signal Tracing

3 Start running your target application. Type

+tg

tg.start

start(tg)

The target PC displays the following message:

System: execution started (sample tim e: 0.0000250)

4 Create a scope to be displayed on the target PC . For example, to create a

scope with an identifier of

sc2=tg.addscope('file', 2)

2 and a scope object name of sc2,type

sc2=addscope(tg, 'file', 2)

5 List the properties of the scope object. For example, to list the properties of

the scope object

sc2

sc2,type

The MATLAB window displays a list of the scope object properties. Notice that the scope properties of type

target.

xPC Scope Object

Application = xpcosc ScopeId = 2 Status = Interrupted Type = File NumSamples = 250 NumPrePostSamples = 0 Decimation = 1 TriggerMode = FreeRun

Time and Data are not accessible with a scope

3-45

3 Signals and Parameters

TriggerScope = 2 TriggerSample = 0 TriggerSignal = -1 TriggerLevel = 0.000000 TriggerSlope = Either ShowSignals = off FileName = unset Mode = Lazy WriteSize = 512 AutoRestart = off DynamicFileName = off MaxWriteFileSize = 536870912

Note that there is no name initially assigned to FileName.Afteryoustart the scope, xPC Target as signs a name for the file to acquire the signal data. This name typically consists of the scope object name,

ScopeId,andthe

beginning letters of the first signal added to the scope.

6 Add signals to the scope object. For example, to add Integrator1 and

Signal Generator,type

3-46

sc2.addsignal ([4,5])

addsignal(sc2,[4,5])

The target PC displays the following messages.

Scope: 2, signal 4 added Scope: 2, signal 5 added

After you add signals to a scope object, the scope of type file does not acquire signals until you start the scope.

7 Start the scope. For example, to start the scope sc2,type

+sc2

sc2.start

Signal Tracing

start(sc2)

The MATLAB window displays a list of the scope object properties. Notice that

FileName is assigned a default filename to contain the signa l data for

the scope of type name,

ScopeId, and the beginning letters of the first signal added to the

file. This name typically consists of the scope object

scope.

Application = xpcosc

ScopeId = 2 Status = Pre-Acquiring Type = File NumSamples = 250 NumPrePostSamples = 0 Decimation = 1 TriggerMode = FreeRun TriggerScope = 2 TriggerSample = 0 TriggerSignal = 4 TriggerLevel = 0.000000 TriggerSlope = Either ShowSignals = on Signals = 4 : Integrator1

5 : Signal Generator FileName = c:\sc7Integ.dat Mode = Lazy WriteSize = 512 AutoRestart = off DynamicFileName = off MaxWriteFileSize = 536870912

8 Stop the scope. Type

-sc2

sc2.stop

3-47

3 Signals and Parameters

stop(sc2)

9 Stop the target application. In the MATLAB window, type

-tg

tg.stop

stop(tg)

The target application on the target PC stops running, and the target PC displays messages similar to the following.

minimal TET: 0.00006 at t ime 0.004250 maximal TET: 0.000037 at t ime 14.255250

3-48

To access the contents of the signal data file that the xPC Target scope of type

file creates, use the xPC Target file system object (xpctarget.fs)fromthe

host PC MATLAB window. To view or examine the signal data, you can use the

readxpcfile utility with the plot function. For further details on the

xpctarget.fs file system object and the readxpcfile utility, see Chapter 9,

“Working with Target PC Files and File Systems”.

Signal Tracing with xPC Target Scope Blocks

Use host scopes to log signal data triggered by an event while your target application is running. This topic describes how to use the three scope block types.

Note xPC Target supports ten target scopes. It can support an infinite number of host scopes, as long as the target PC resources can support them. It can support eight file scopes. Each scope of type 10 signals. Each scope of type

file or host can contain an infinite number of

signals, as long as the target PC resources can support them.

target can contain up to

Signal Tracing

Note If your model has the output of a Mux block connected to the input of an xPC Target Scope block, the signal might not be observable. To ensure that you can observe the signal, add a unity gain block (a Gain block with a gain of

1) between the Mux block and the xPC Target Scope block.

Using xPC Target Scope Blocks from Referenced Models

You cannot add any type of xPC Target scope to a referenced model. Doing so causes an error. You can add only an xPC Target scope to the topmost model. If you want to log signals from referenced models, you can do so with the logging mechanism in xPC Target Explorer or with the xPC Target scope objects.

Scope of Type Host

For a scope of type host, the scope acquires the first N samples into a buffer. You can retrieve this buffer into the scope object property then stops and waits for you to manually restart the scope.

sc.Data.Thescope

The number of samples

N to log after triggering an event is equal to the value

you entered in the Number of Samples parameter.

SelectthetypeofeventintheBlockParameters: Scope (xPC Target) dialog boxbysettingTrigger Mode to or

Scope Triggering.

Signal Triggering, Software Triggering,

ScopeofTypeTarget

For a scope of type target,loggeddata(sc.Data and sc.Time)isnot accessible over the command-line interface on the host PC. This is because the scope object status ( completes one data cycle (time to collect the number of samples), the sco pe engine automatically restarts the scope.

If y ou create a scope object, for example, of type

target, and then try to get the logged data by typing sc.Data,you

get an error message:

Scope # 1 is of type 'Target'! Property Data is not accessible.

sc.Status)isneversettoFinished. Once the scope

sc = getscopes(tg,1) for a scope

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3 Signals and Parameters

If you want the same data for the same signals on the host PC while the data is displayed on the target PC, you need to define a second scope object with type

host. Then you need to synchronize the acquisitions of the two scope

objects by setting TriggerMode for the second scope to

'Scope'.

Scope of Type File

For a scope of type file, the scope acquires data and writes it to the file named in the FileName parameter in blocks of size WriteSize.Thescope acquires the first of length Number of Samples. The memory buffer writes data to the file in WriteSize chunks. If the AutoRestart check box is selected, the scope then starts over again, overwriting the memory buffer. The additional data is appended to the end of the existing file. If the AutoRestart box is not selected, the scope collects data only up to the number of samples, and then stops. The number of samples value you entered in the Number of Samples parameter. If you stop, then start the scope again, the data in the file is o verwritten with the new data.

SelectthetypeofeventintheBlockParameters: Scope (xPC Target) dialog boxbysettingTrigger Mode to or

Scope Triggering.

N samples into the memory buffer. This memory buffer is

N to log after triggering an event is equal to the

Signal Triggering, Software Triggering,

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Signal Tracing with Simulink External Mode

You can use Simulink external mode to establish a communication channel between your Simulink block diagram and your target application. The block diagram becomes a graphical user interface to your target application and Simulink scopes can acquire signal data from the target application. For each Simulink scope, the xPC Target software adds an xPC Target scope of type host to the system to upload signals. You can control which signals to upload through the External Signal & Triggering dialog box (see “Signal Selection” in the Real-Time Workshop

Note Do not use Simulink external mode while xPC Target Explorer is running. Use only one interface or the other.

User’s Guide.

Signal Tracing

Limitations

The following are limitations of uploading xPC Target signals to Simulink external mode:

• When setting up signal triggering (Source set to signal), you must explicitly

specify the element number of the signal in the Trigger signal:Element field. If the signal is a scalar, enter a value of signal, enter a value from

1 to 10. D o not enter La st or Any in this field

1.Ifthesignalisawide

when uploading xP C Target signals t o Simulink scopes.

• The Direction:Holdoff field has no effect for the xPC Target signal

uploading feature.

Before You Start

The procedures in this topic use the Simulink model xpcosc.mdl,which already contains a Simulink Scope block, as an example. After you download your target application to the target PC, you can connect your Simulink model to the target application.

Signal Tracing with External Mode Example

This procedure assumes that you have downloaded your target application to the target PC.

Note that this procedure edits the Simulink window External Mode Control Panel and assumes that you are familiar with that dialog box. See “External Mode Control Panel” in the Real-Time Workshop User’s Guide for details of the Simulink external mode dialog box.

1 In the MATLAB window, type

xpcosc

2 In the Simulink window, a nd from the Tools menu, select External Mode

Control Panel.

The External Mode Control Panel dialog box opens.

3 Click the Signal & Triggering

The E xternal Signal & Triggering dialog box opens.

button.

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3 Signals and Parameters

4 Ensure that the Source parameter is set to manual.

5 Set the Mode parameter to normal. This ensures that the scope acquires

data continuously.

6 Select the Armwhenconnectingtotargetcheck box.

7 In the Duration box, enter the number of samples for which external mode

is to log data. The External Signal & Triggering dialog box should look similar to the figure shown.

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8 Click Apply,thenClose.

9 In the Simulink window, increase the simulation stop time. For example,

enter

Signal Tracing

10 From the File menu, select Save As and enter a filename. For example,

enter

my_xpc_osc6.mdl and then click OK.

11 Build and download the target application. In the Simul ink window and

from the Tools menu, select Real-Time Workshop.FromtheReal-Time Workshop submenu, select Build Model.

The xPC Target software downloads the target application to the default target PC.

12 In the Simulink window, and from the Simulation menu, select External.

A check mark appears next to the menu item External, and Simulink external mode is activated.

13 If a Scope window is not displayed for the Scope block, double-click the

Scope block.

A Scope window is displayed.

14 In the Simulink window, and from the Simulation menu, select Connect

to target.

15 From the Simulation menu, select Start Real-Time Code.

The target application begins running on the target PC and the Scope window displays plotted data.

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3 Signals and Parameters

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Signal Tracing with a Web Browser

The Web brow ser interface allows you to visualize data using a graphical user interface.

After you connect a Web browser to the target PC, you can use the scopes page to add, remove, and control scopes on the target PC:

1 In the left frame, click the Scopes button.

The browser loads the Scopes List pane into the right frame.

2 Click the Add Scope button.

Ascopeoftype Scopes pane displays a list of all the scopes present. You can add a new

target is created and displayed on the target PC. The

Signal Tracing

scope, remove existing scopes, and control all aspects of a scope from this page.

Tocreateascopeoftype Scope button to select

3 Click the Edit button.

host, use the drop-down list next to the Add

Host.ThisitemissettoTarget by default.

The scope editing pane opens. From this pane, you can edit the properties of any scope, and control the scope.

4 Click the Add Signals button.

The browser displays an Add New Signals list.

5 Select the check boxes next to the signal names, and then click the Apply

button.

A Remove Existing Signals list is added above the Add New Signals list.

You do not have to stop a scope to make changes. If necessary, the Web interface stops the scope automatically and then restarts it when the changes are made. It does not restart the scope if the state was originally stopped.

When a host sco pe is stopped (Scope State is set to one cycle of acquisition (Scope State is set to

Interrupted)orfinishes

Finished), a button called Get

Data appears on the page. If you click this button, the scope data is retrieved in comma-separated value (CSV) format. The signals in the scope are spread across columns, and each row corresponds to one sample of acquisition. The first colum n always corresponds to thetimeeachsamplewasacquired.

Note If Scope State is set to Interrupted, the scope was stopped before it could complete a full cycle of acquisition. Even in this case, the number of rows in the CSV data will correspond to a full cycle. The last few rows (for which data was not acquired) will be set to

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3 Signals and Parameters

Signal Logging

In this section...

“Introduction” on page 3-56

“Signal Logging with xPC Target Explorer” on page 3 - 56

“Signal Logging in the MATLAB Interface” on page 3-59

“Signal Logging with a Web Browser” on page 3-63

Introduction

Signal logging is the process for acquiring signal data during a real-time run, stopping the target application, a nd then transferring the data to the host PC for analysis. This is also known as real-time data streaming to the target PC. You can plot and analyze the data, and later save it to a disk. xPC Target signal logging samples at the base sample time. If you have a model with multiple sample rates, add xPC Target scopes to the model to ensure that signals are sampled at their appropriate sample rates.

3-56

Note The xPC Target software does not support logging data with decimation.

Note xPC Target Explorer works with multidimensional signals in

column-major format.

Signal Logging with xPC Target Explorer

You plot the outputs and states of your target application to observe the behavior of your model, or to determine the behavior when you vary the input signals and model parameters.

This procedure uses a model named assumes you have created a target application and downloaded it to the target PC. The with the xPC Target Scope block removed.

xpc_osc4.mdl is the same as the my_xpc_osc3.mdl tutorial model

xpc_osc4.mdl as an example and

Mathworks XPC TARGET 4 user guide

Specifications and Main Features

Frequently Asked Questions

User Manual