MATLAB: Simulink to C-Code, Problem with “Variable Transport Delay” (Access Violation)

access violationcc codesimulinksimulink codervariable transport delay

Hello,
I have a problem embedding c-code which was generated by Matlab/Simulink in a VS C++ 2010 Express-project:
What I did:
– Use "Code Generation"/"Build" to create c-code (using grt.tlc)
– Create new c-project using Visual C++ 2010 Express
– copy all files to the project and include "mySimulinkFunction" in "myProgramm.c"
.
Sequence of execution (myProgramm.c):
main() {
 mySimulinkFunction_initialize(1)
 rtmSetTFinal(mySimulinkFunction_M,10)
while (t<tFinal){
 mySimulinkFunction_output(1)
 mySimulinkFunction_update(1)
}
}
.
This one worked fine for a simple Simulink-model. Now I have another simple model which contains a "variable transport delay" (Input->VTD->Output). Unfortunately, I can't execute this one, if I set the time-delay > 0. The error occurs in this line (looking at mySimulinkFunction.c):
if ((tMinusDelay <= tBuf[oldestIdx]))
…
with tMinusDelay > 0 and oldestIdx = 0 and tBuf = 0x00000000
There is an access violation while reading at position 0x0 (code 0xC0000005).
Can anyone help me figure out how to solve the problem? Because the code was generated automatically there are 2 possible solutions:
– I have to make some preparations before generate the code (in Simulink)
– My way of embedding the code is wrong and I have to do some rework there
Robert
PS: By the time this problem is solved, I also may need some help embedding "Simulink with Simscape" generated c-code in a vs-project. This one did not work at all (until now).

Best Answer

The main() used for executing the generated code is in $matlabroot/rtw/c/grt/grt_main.c - perhaps you can follow the same sequence to make sure that all initialization is done correctly?
Just FYI, if you plan to do this type of customization more extensively, I would recommend using ert.tlc which ships with Embedded Coder - the generated code is easier to read and more optimized.
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