Help on shared libraries from Labview to Labwindows

Hello,

My problem is: I have a spectrometer HR 4000 from Ocean Optics. I want to control it from labwindows and, from that, integrate it to other labwindows program.

I have .vi from NI to control the spectrometer from labview:

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=7833BD4A31DA1274E04400144FB7D21D

The .vi works perfectly with the spectrometer.

Then, I build a shared libraries with the usual procedure with the .vi I need. I have now a .h, .lib and .dll.

.h is given at the end.

What I do is:

I use the viFindRsrc function to have a char of my instrument.

The function from the labview needs a VISA ressource name.

From this subject: http://forums.ni.com/t5/LabVIEW/How-to-pass-Visa-Resoure-Name-parameter-to-labview-dll-in/td-p/2498400

I know that I need to put a string control to a VISA ressource name.

What I did: I use that program:

http://digital.ni.com/public.nsf/allkb/4737E4A5E44A81D38625698500576617

I rebuilt the shared libraries with this program and the other .vi I need to control the spectrometer.

Then I call StrToVISAIo first, and the reste after.

What I have is:

uintptr_t VISAResourceNameOut;
Cluster SpectralWaveform;
int32 elmtCount=32000;
AllocateDoubleArray1 (elmtCount);
AllocateDoubleArray (elmtCount);

StrToVisaIO(instrDescriptor, &VISAResourceNameOut);
OceanOptics20004000_Initialize(&VISAResourceNameOut, &VISAResourceNameOut);

OceanOptics20004000_ReadSpectralWaveform(&VISAResourceNameOut, &VISAResourceNameOut, &SpectralWaveform);
OceanOptics20004000_Close(&VISAResourceNameOut);         

Where instrDescriptor is a char I get with  viFindRsrc, that's not the problem.

Everything compile fine, but, when I want to know what's in SpectralWaveform, I get:

SpectralWaveform.elt1 and SpectralWaveform.elt2 are unitilialized.

Here is the full .h

#include "extcode.h"
#pragma pack(push)
#pragma pack(1)


#ifdef __cplusplus
extern "C" {
#endif
typedef struct {
	int32_t dimSize;
	double elt[1];
} DoubleArrayBase;
typedef DoubleArrayBase **DoubleArray;
typedef struct {
	int32_t dimSize;
	double Numeric[1];
} DoubleArray1Base;
typedef DoubleArray1Base **DoubleArray1;
typedef struct {
	DoubleArray elt1;
	DoubleArray1 elt2;
} Cluster;

/*!
 * StrToVisaIO
 */
void __cdecl StrToVisaIO(char String[], uintptr_t *VISAResourceName);
/*!
 * Establishes communication with the instrument and optionally performs an 
 * instrument identification query and/or an instrument reset.  It also places 
 * the instrument in a default state needed for other instrument driver 
 * operations.  Therefore, call this VI before calling other instrument driver 
 * VIs for this instrument.  Generally, you need to call the Initialize VI 
 * only once at the beginning of an application.
 */
int32_t __cdecl OceanOptics20004000_Initialize(uintptr_t *VISAResourceName, 
	uintptr_t *VISAResourceNameOut);
/*!
 * Performs an instrument error query before terminating the software 
 * connection to the instrument.
 */
int32_t __cdecl OceanOptics20004000_Close(uintptr_t *VISAResourceName);
/*!
 * Configures the integration time of the spectrometer. The integration time 
 * is the amount of time that the device collects light before digitizing it 
 * and sending it out over the USB.  The longer the integration time, the more 
 * light it may collect. 
 */
int32_t __cdecl OceanOptics20004000_ConfigureIntegrationTime(
	uintptr_t *VISAResourceName, uint32_t IntegrationTime6000, 
	uintptr_t *VISAResourceNameOut);
/*!
 * Displays the spectrum vs wavelength in a waveform graph.
 * 
 * <b>Note:</b>  Do not put this VI in a loop if performance is a concern.  
 * Please see the <b>Ocean Optics 2000 4000 Acquire Continuous Waveform</b> 
 * example for an example of how to do continuous acquisition.
 * 
 * 
 */
int32_t __cdecl OceanOptics20004000_ReadSpectralWaveform(
	uintptr_t *VISAResourceName, uintptr_t *VISAResourceNameOut, 
	Cluster *SpectralWaveform);
/*!
 * Returns the intrument status information. Information included are number 
 * of pixels, intergration time, packets in spectra, packet count, USB speed 
 * and Lamp status.
 * 
 * <B>Note:</b>
 * Not supported by USB2000 and HR2000
 */
int32_t __cdecl OceanOptics20004000_QueryStatus(uintptr_t *VISAResourceName, 
	uint16_t *USBSpeed, LVBoolean *LampStatus, uint8_t *PacketCount, 
	uint8_t *PacketsInSpectra, uint32_t *IntegrationTime, 
	uintptr_t *VISAResourceNameOut, uint16_t *NumberOfPixels);

MgErr __cdecl LVDLLStatus(char *errStr, int errStrLen, void *module);

/*
* Memory Allocation/Resize/Deallocation APIs for type 'DoubleArray'
*/
DoubleArray __cdecl AllocateDoubleArray (int32 elmtCount);
MgErr __cdecl ResizeDoubleArray (DoubleArray *hdlPtr, int32 elmtCount);
MgErr __cdecl DeAllocateDoubleArray (DoubleArray *hdlPtr);

/*
* Memory Allocation/Resize/Deallocation APIs for type 'DoubleArray1'
*/
DoubleArray1 __cdecl AllocateDoubleArray1 (int32 elmtCount);
MgErr __cdecl ResizeDoubleArray1 (DoubleArray1 *hdlPtr, int32 elmtCount);
MgErr __cdecl DeAllocateDoubleArray1 (DoubleArray1 *hdlPtr);

#ifdef __cplusplus
} // extern "C"
#endif

#pragma pack(pop)

 Everything compile fine, and when I run it, I have no error.

So whether I'm not giving it the good VISA ressource name (maybe I should change the string inside the .vi, but not sure how to do that), whether something with the pointer is quite wrong (see the prototype function in the .h). Maybe I need to initialize SpectralWaveform.elt1 and SpectralWaveform.elt2 corrrectly. But not sure how to do this either, with this struct.

What I want at the end is to display the spectrum.

Any idea ?

Best Regards,

Geoffrey.