Generating an S-function that calls a C++ library

Transcription

1 Generating an S-function that calls a C++ library This document presents two different procedures in order to run a model with an S-Function that calls a C++ library. Run-time procedure : all the files are already generated, user can directly load the model with RT-Lab. Developer procedure : all the process is fully detailed (creation of the library, of the mex32 files, RT-Lab building process, etc )

2 RUN-TIME PROCEDURE This package allows the use of the files as they are, and directly compile the project under RT-Lab environment. Software Versions : RT-Lab MATLAB R2010B QNX Package Run-time package.zip contains : cpp_example.mdl : model implementing the S-function block sfun_extern_cpp_call.c : source code of the S-Function implemented in the model sfun_extern_cpp_call.mexw32 : compiled file of the S-function, which allows offline simulation of the model counter.a : library for QNX, whose functions will be called by the S-Function counter.h : header file of the library cpp_example.llm, cpp_example.probe, cpp_example_2_sc_user_interface.mdl, report, Opcommon, cpp_example_sm_computation : files and directories generated automatically by RT-Lab during building process. Procedure Unzip thz file Run-time package.zip In RT-Lab, create a new project Add the model cpp_example.mdl to the project Assign the nodes (QNX target) Load and execute.

3 DEVELOPER PROCEDURE This section describes the entire procedure to achieve the same result as in the Run-time configuration. It assumes that your host environment is Windows and that target OS is QNX Package : cpp_example.mdl : model implementing the S-function block sfun_extern_cpp_call.c : source code of the S-Function implemented in the model counter.cpp : C++ source code of the (future) library counter.h : header file of the library counter.cpp : library generated from C++ source code First, we are going to make the model run in Windows environment 1) Compile the counter.cpp code for Windows to get a library (*.lib) file The *.lib file is needed further to be linked to the S-Function code, so that we can run the model offline (note : counter.lib file is already provided in the Developer Package) Use your C/C++ development environment (Visual Studio, Code::Blocks, etc ) to create a static library project. Add counter.cpp as a source file and counter.h as a header filer. Build the project. You should get a *.lib file. Let s call it counter.lib. 2) Compile the S-function code to get the *.mexw32 file The *.mexw32 file is needed to execute the model offline. Open MATLAB Set the current working directory as being the one which contains the files of the Developer Package. Type the command : mex sfun_extern_cpp_call.c counter.lib You should get a file called sfun_extern_cpp_call.mexw32 Open the Simulink model cpp_example.mdl and check that you can execute it offline. Now that the model works offline, let s perform some steps to make it work in real-time

4 3) Compile the counter.cpp code for QNX to get a library (*.a) file This file is needed to perform the building process in QNX, to get a real-time executable Make sure your host PC is connected to the QNX target (you can ping the target) Open an Explorer window and type the command ftp://xxx.xxx.xxx.xxx/ in the address bar, where XXX.XXX.XXX.XXX is the IP address of the target Connect to the session using the following credentials o User : ntuser o Password : ntuser You are now connected to the target. Create a new folder counter and open it.

5 Transfer to the target the files : counter.cpp, counter.h and go Open a cmd window (Start Execute cmd) Connect to the target using telnet protocol : telnet XXX.XXX.XXX.XXX, where XXX.XXX.XXX.XXX is the IP address of the target

6 Login as root Go to the counter folder that you created above : cd /home/ntuser/counter Type command ls : you should see the files counter.cpp, counter.h and go in the current folder Type command chmod 777 go Type command textto l go (this is a lower-case L ) Type command./go v7.11 counter.a ( v7.11 represents the MATLAB version. This has to be adapted depending on the version you are using). This generates the counter.a file Go back to the Explorer window connected with FTP, get back the counter.a file, and paste it in the working folder, along with the model and the other files.

7 4) Build the project with RT-Lab Open RT-Lab and create a new project Import the following files : cpp_example.mdl, counter.a, counter.h, sfun_extern_cpp_call.c,sfun_extern_cpp_call.mexw32 In RT-Lab, in the Development tab, make sure that the Target Platform is QNX 6.x In RT-Lab, in the Development tab, add the file counter.a in the Libraries tab In RT-Lab, in the Files tab, add the following files o counter.a, in binary mode, before compilation o sfun_extern_cpp_call.c, in ascii mode, before compilation o counter.h in ascii mode, before compilation Build, load and execute the model