How to make a driver using DLL in LabVIEW?

[Jacky Wei]

I had followed the "Using Exteranal Code in LabVIEW" manual having finished the making dll file, and the lsb file(I attempted that two ways). But when I load the code in LabVIEW, it can't work. I don't know what had happened, I only got a error message like this:"'0x100014f1'commond call memory'0x00000000',this memory can't be written" or other similar error message, if I push the "enter" button, the vi application which I having lunched will crash. If I push the "cancel" button, the debug model will start,and the next message is "Unhandle exception in LabVIEW.exe(MSVCRTD.DLL/LVS95.TMP/COUNTER.DLL(the last one is creat by myself)):0xC0000005:Access Violation", but I wonder what had cause this? My DLL had been made successf
ully under the VC++6.0, why LabVIEW can't call it fluently? How to make a driver for my own device using LabVIEW? How to correct my error to finished my hole work? Thank you very much. Jacky Wei

[Oleg]

Hi,
Check the "calling conventions" which you use in configuration dialog of your call library node.
Usually errors with memory exist due to the using of illegal calling conventions ("C" or "std call (WINAPI)"). You have to select there the conventions you used during the compiling of your dll.
Try different, it may help.

Good luck.

Oleg Chutko.

[Jacky Wei]

I had changed it, but the same error message apeared. Can you tell me are there any other possible error happened? and how to debug and correct it? thank you very much.

[Oleg]

1. Can you call this DLL from within VC?
2. What operation system do you use? There may be a problem with calling of win95 dll under NT or win2000 for example.
3. If you use NT you may not have permissions to work with some ports and memory areas.
4. Under NT or win200 try to compile the library as a 32-bit dll, and under win95 - as 16-bit one.

Good luck.

Oleg Chutko