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Hello all, background A while ago I wrote a dll wrapper to get data from dedicated test-hardware. For this hardware there is a dll available. To use this dll you need to use an callback function. If you need to use a dll in Labview which needs a callback you need to write the callback in C code and use a Labview C lib to get the data into Labview, basically my dll takes care of this problem . Enhance the code and way of working more efficient The code I wrote code works fine. However I did not use / test it for hours on a row. And sometimes If I make a mistake when changing the code I run into problems. I was able to fix all the errors and problems however it was not the most efficient way of working. For instance If there is a serious error in the code the dll I need for the hardware can crash, it can make my wrapper crash, which will in return make Labview crash. This makes the way of coding inefficiënt and it will not enable me to read my C++ book etc etc. Example pseudo code I did try to extract some main points of intrest from the code, I did add some comment in the code. I hope someone can give me some general guideline or advice what to read. At this time I am reading: Unhandled C++ exceptions I think I might be able to use it, I did not use this before so advice would be welcome. Thank you all for the help ! // .. // This is a part of the code only intended to have a talk about how to catch errors // It is not complete and intended as Pseudo code // .. int __stdcall MyDriverLoads(const int NumberToInitialise,const bool enableAnotherOption , const char *const path , LVUserEventRef *rwer) { // loads the dll // Q -- I can check if (F_functionname !=0), if it is not 0 then I can proceed if the function returns 0 I can return an error to Labview Extern_dll = Load_Extern_dll(); // Get the functions I need from the dll p2_ExternDriver F_ExternDriver = (p2_ExternDriver)GetProcAddress(Extern_dll, "_ExternDriver"); p2_Initialise F_Initialise = (p2_Initialise)GetProcAddress(Extern_dll, "_Initialise"); p2_AdapterCount F_AdapterCount = (p2_AdapterCount)GetProcAddress(Extern_dll, "_AdapterCount"); p2_StartLogging F_StartLogging = (p2_StartLogging)GetProcAddress(Extern_dll, "_StartLogging"); p2_StopLogging F_StopLogging = (p2_StopLogging)GetProcAddress(Extern_dll, "_StopLogging"); // When there are adapters found I tell it in Labview adapterCount = F_AdapterCount(); // Get the callback function adress, if adress == 0 I can see something is wrong void(__stdcall *p2_CallbackFunction_t) (pt2Obj , const LogData & ) = &CallbackFunction; // Q -- I could use try {} and catch {} however I do not have acces to the source code of the dll so, // I do not know if they used // trow "The Blue error" , or // trow "The Red error" ret = F_ExternDriver(adapterCount, enableLogFile, path, *p2_CallbackFunction_t, pt2Obj); // This tels the dll to start logging before this command you will not receive data in Labview ret F_StartLogging(1,2,3); // Labview is receiving data thats great !!! return ret; // Q -- Labview has been receiving data for a hour what happens if the used extern dll crashes ?? // If the dll crashes when return is passed I can not use try() and catch anymore. // } extern void __stdcall CallbackFunction(pt2Obj , const LogData & ) { // There is a lot to do here // do stuff!! // I did not write everything here err = PostLVUserEvent(*event_ref, &tmpEvent); }

Hello everyone, I am working on putting together a test executive that pulls from a lot of external code libraries. I'm at the point now that I have a fair number of custom error codes generated by different DAQ libraries and keeping track of all of them is becoming increasingly difficult. I've been using error rings for custom error generation and while not ideal has served well enough until now. Keeping track of the codes hasn't been hard because they are few and far between. I've been thinking about transitioning to a custom error file instead of using ring constants because keeping track of it all is not realistic anymore. My question arises from the fact there are ~10 different libraries in this current project all pulling from 3-4 different source control locations and creating a single error file that covers all the errors from these libraries seems incorrect. I would think custom error records would travel with the library that uses them, but does this create file reference headaches when you start pulling in libraries and external references, PPLs, etc? Question: How do you keep track of your custom error codes? Some options that I could see being viable: A single company wide error code file that gets pulled down with your version control. A blanket approach would make sense and also would prevent error code conflicts from one library to another by forcing communication during modification and addition. Error code files packaged with each individual library and pull them all into projects when they are getting developed. This seems the most modular and portable but could result in conflicts with error code numbers if developers don't communicate about the ranges they are using; also how does LabVIEW do with referencing lots of different error files. Cheers, Tim

Hi all, I am supporting a legacy application in LV2010, running on a realtime PXI controller. The application is throwing occasional TDMS errors, typically -2505, when I do TDMS Flush or TDMS Close operations. The description of this error is simply "LabVIEW failed to write data to the TDMS file," which doesn't really tell me what happened. Every time I write or flush, the same quantity of data is being written, and most of the time, it operates as expected. After iterating for anywhere between 2 and 14 hours, though, it eventually throws the error. Does anyone know in more detail what this error means, and how to deal with it? Thanks!