Problems with Visual Studio 6.0


I have downloaded the visual studio 6.0, okxem.lib file. But I still get linking problems. I have no idea whats missing.

My errormessages are:

DatakortConsole.obj : error LNK2001: unresolved external symbol “public: __thiscall okCUsbXEM3001v2::okCUsbXEM3001v2(void)” (??0okCUsbXEM3001v2@@QAE@XZ)
DatakortConsole.obj : error LNK2001: unresolved external symbol “public: __thiscall okCUsbFrontPanel::~okCUsbFrontPanel(void)” (??1okCUsbFrontPanel@@QAE@XZ)

And my simple program:
#include “stdafx.h”
#include “okCUsbFrontPanel.h”

int main(int argc, char* argv])
// Declarations:
okCUsbXEM3001v2 comUSBDriver;

return 0;


Shouldn’t this work?

Hi Rick-

It would seem that you’re using the VC6 library posted to the Software Downloads section of the forum. This VC6 library has been updated and is now included in the standard FrontPanel distribution. After installation, look in

c:\Program Files\Opal Kelly\FrontPanel\API

There is a library called okFrontPanel-vc6.lib. That one will include the constructor for the okCUsbXEM3001v2 board.

We try to remove dated attachments from the forum, but that one snuck through. I will post a notice on that topic and remove the attachment. Sorry for the inconvenience.

Let me know if the new library works for you.


I tried to use okFrontPanel-vc6.lib, but I have to ignore LIBCD.lib, otherwise I get errormessages. It seem to work now. Should LIBCD.lib be ignored? Or is something still wrong?

Thanks for the fast reply!

Nothing is wrong. You can safely ignore LIBCD.lib.

thanks for your help!

I have the same problem as Rick. What is LIBCD.lib and why it gave us such errors like this???

SVCRT.lib(MSVCRT.dll) : error LNK2005: __close already defined in LIBCD.lib(close.obj)
MSVCRT.lib(MSVCRT.dll) : error LNK2005: __lseek already defined in LIBCD.lib(lseek.obj)
LINK : warning LNK4098: defaultlib “MSVCRT” conflicts with use of other libs; use /NODEFAULTLIB:library
LINK : warning LNK4098: defaultlib “LIBCMT” conflicts with use of other libs; use /NODEFAULTLIB:library
Debug/Test_10_02_05.exe : fatal error LNK1169: one or more multiply defined symbols found


You may be interested in reading about the run-time libraries on the Microsoft MSDN website:,vs.80).aspx

libcd is the single-threaded C run-time library from VC6.


Thank you for quick replying. I have another stupid question. How do you ignore the libcd.lib??? Thank you so much.

I’m not entirely sure how to do it with VC6. However, in the project properties of VC7, there is a frame and configuration point that allows you to “ignore specified libraries”. At that option, you simply list the libs you want to ignore such as “libcd”.

This option is under the linker configuration.