It is known that MATLAB provides the thrid-party blocks for SCRAMNet cards to transfer data in real-time based on xPC Target. But now we want to transfer data calculated from Simulink model (run in Windows operation system) to SCRAMNet card installed in the same computer. Does anyone know how to achieve this goal?
Thanks and regards,
Fei Zhu
Dear Fei Zhu,
You can contact with Mathwork, because it so interest point
Yes, you can write an S-Function to implement the C++ code. Assuming you have the SCRAMNet drivers loaded and working on your machine (in my case, the 64-bit drivers), this code should work for you to read and write a floating point 4 byte block of data. You can make sure your SCRAMNet device works using the SCRAMNet Monitor program that comes in the package.
Run the BUILD.m file to compile the mex code and then open and run the Simulink model. Double click the Read block to change the memory address parameter. I left Read to 0 and Write to 1 for now. Let me know if this works for you. I can provide more assistance or code if you need.
Inside each C file is the code to initialize the SCRAMNet device on model start.
Fei,
Yes, please let me know how it works out for you. I am glad to help out further if you need more.
Attached is the 32 bit version of the SCRAMNet+ SC150 library and headers. This doesn't work with the GT200 line of SCRAMNet. In order to compile code for the GT200, you need to have that API and library. To download the software, go here:
https://www.curtisswrightds.com/products/cots-boards/io-communication/shared-memory/scramnet-gt.html
You should be able to follow my SC150 example and substitute the GT200 headers and libraries. For example, in the GT Software for Windows, the "inc" folder has the header files you need and the "win2k/lib" folder has the library file. I think replacing these directories in the MATLAB BUILD file I have initially and then rewriting the code to use the new API will work.
In the Software manual on the same link above, "Section 3.4.2 Preparing for GT Memory Access" describes how to interact with the device.
With both the readscrfloat.c and writescrfloat.c files, you need to edit two methods:
static void mdlStart(SimStruct *S)
static void mdlOutputs(SimStruct *S, int_T tid)
If you look in the source file, under "win2k/VisualC/sineWave.c", you will see a detailed example of how to initialize and read/write to memory space. Also, under "win2k/LabWindows/gtRead.c" is another example of reading.
I put together an example "GTreadscrfloat.c" file which I think is a good start for the GT code. You can use this to replace the existing "readscrfloat.c" file. I don't know if it works as is, so you will have play with it. I hope this enough for you or anyone else interested to work with.
Dear Thomas,
How are you? I am sorry to disturb you again. With the source code you provided, now we can run some simple numerical simulation successfully with SCRAMNet card in Windows platform. However, we met a new question when we tried to enlarge the calculation scale. The following figure shows the schematic Simulink model. GTreadscrfloat and GTwritescrfoatref23, coded by S-function, are the read and write block connected to SCRAMNet card. This two S-function are modified based on your version. In each time step, these two blocks only read and write the data with 1×1 dimension. Numerical Simulation block is the implementation of matrix operations.
During the execution of this model with a fixed time step, this model can run successfully when N is a small value; and when N increases to a certain value, this model cannot run with an error of:
Error reported by S-function “GTwritescrfoatref23”: scgtMapMem returned NULL
Since these two blocks GTreadscrfloat and GTwritescrfoatref23 read and write the data with 1×1 dimension in each time step, which is unrelated to the number of N, we cannot understand why this error appears.
According to the SCRAMNET GT Software and API Guide，this error indicates the GT memory cannot be mapped into the program's address space. We modified the address in S-function but it was of no use. So we hope you can give us some suggestion to solve this error since you are professional on SCRAMNet card. Thanks in advance.
Best regards,
Fei
Sorry, I did not get any notifications on this thread so I did not know there was an outstanding question. Let me see if I can be of any help.
Which S-Function is reporting the error? The GTread or GTwrite? The "N" variable shouldn't create a problem here as the scgtMapMem function is meant to set the base memory pointer and has nothing to do with input size.
Do you ever see this error with N = 1? When does the error happen? N >= 2?
Dear Thomas,
Sorry to reply to you so late. These days we are trying in vain to find the solution for this question by ourselves. The attached file is the Simulink model we used.
Run the initial.m to run the Simulink model (SCRAMNetTest.slx). When the variable n in initial.m is selected larger than 3700, then an error occurs which you can see it in block_error.png “scgtMapMem returned NULL”. It has been verified that this error is no relationship with the sample time. So we hope you can help us to check this error if you have time. Thanks in advance.
Fei
Please try the Speedgoat GT200 library blocks instead:
https://www.speedgoat.ch/ Products/IOmodules- SharedMemory.aspx
http://www.speedgoat.ch/ downloads/sglib/speedgoat_8. zip
You can install their driver package, run 'speedgoatlib' and try the IO901 or IO902 blocks depending on your GT200 hardware.
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