ShowDataSocketError is a utility function that is written in the C file of the examples. Open the example and right-click on the function and click Go To Definition... and you will see that it is just written write there in the C file. This is the source for it.
static void ShowDataSocketError(HRESULT errorCode)
{
char errBuf[300];
DS_GetLibraryErrorString (errorCode, errBuf, 300);
MessagePopup ("Error", errBuf);
return;
}
Best Regards,
Chris Matthews
National Instruments