RT startup applicatio​n with C code DLLs deployment problem

Question

Hi!
I work with LV  8.2  at host PC and LV RT 8.2 at PXI RT 8186 controller.
I have made VI which uses some C code from one of my DLLs. For making DLL I used CVI. My VI with DLL is working good when deployed on RT directly from developer interface. So I wanted to make startup apllication out of that VI. I used build application tool (Build Specifications) at Project Manager.
Target destination directory for startup application was set as c:\ni-rt\startup.  Looking at Generate Preview before engaging build,  startup.rtexe was listed to go at c:\ni-rt\startup folder and DLL was automaticaly added through include if referenced option into  c:\ni-rt\startup\data folder.
There where no build errors and startup.rtexe was sucessfully built and saved at my procject's destination folder at my host PC. After that I tryed deploying that application at my RT target and I would get : Failled to deploy error.
When I  look at  c:\ni-rt\startup   folder on rt target, after failed deployment,  I can see application files copied (strartup.rt exe to:\ni-rt\startup, and DLL to :\ni-rt\startup\data), and also in ni-rt.ini file I can see expected changes. But when I start my PXI with that startup application it doesn't seem to work at all.
After making several different builds using different destination and support directory options for my VIs, and differently placed checkmarks under Advanced Build Application project properties,  got the same result. Every build was good, but deployment failed.
So after that, I removed DLL calls from my VI and tryed to build startup application, and got good build exe and sucsessfull deployment on RT target and application worked good.
So to summarize it:
                            - I have VI  with some C code used throgh DLL calls using Call Library Functon Node
                            - Path off DLL in that Call Library Function Node is absolute (exe: D:\monitoring\communication\myTCP.dll) at my host PC
                            - DLL is used for establishing TCP/IP communication and it is made with CVI compiler and CVI libraries
                            -I get built application without any error
                            -build automatically includes depending DLL
                            -when running startup application with DLL it doesnt seem to work good (I tryed including some write file VIs to it and it didnt write anything)
                            -when building and running startup applications without DLL calls everything works OK
Is there anything else I have to include in my build besides the dll that I am using in my VI? Has anybody have any idea how to deal with this problem?

Answer 1

Hi Mike,
When you build a CVI DLL for real-time (i.e. you selected the Real-time only option for Run-time support in the Target Settings dialog), that DLL is statically linked to cvi_lvrt.dll located in the windows\system32 directory.  This means that your DLL plus this DLL must be present on the RT target for your application to run. To get the cvi_lvrt.dll to the RT target, you can add it as a support file in your RT application. This will install the cvi_lvrt.dll to the ni-rt\startup\data directory and allow your application to load and run.
Hope this helps!
Best Regards,
Jonathan N.
National Instruments