LabVIEW DLL, ASP.NET

[HCL Tech]

Hi,

I have a test equipment, which has host PC and the PXI chassis connected to host PC through ethernet cable. PXI chassis has LabVIEW 7.1RT, host PC has LabVIEW 7.1 programming language with Windows 2000 OS. I had created a LabVIEW 7.1 dll to measure voltage using ADC present in PXI Chassis in host PC using wrappers placed in LabVIEW RT. This dll is called from ASP.NET application present in host PC.

This DLL was working fine all these days, but now it is not working. The DLL throws -10011 error when called in ASP.NET, but the same DLL works perfectly fine when called from Visual Basic 6.

Need help.

Thanks,

Poornima

[MattP]

Hi Poornima,

According to LabVIEW, that error has the following description: "The analog input scan rate is too fast for the number of channels and the channel clock rate; or the given clock rate is not supported by the associated counter channel or I/O channel."  Are you using the same input parameters to the DLL in both ASP and VB?  Did the DLL work from ASP before?  If so, what changed in the meantime?  This would be completely expected if the sample rate requested is faster than your DAQ board can handle.

[HCL Tech]

Hi,

Thanks for the reply.

I don't understand why the clock rate issue is showing up only when the DLL is called from ASP.NET. If I run LabVIEW VI, it works fine. If I call the DLL from Visual basic it works fine, only when the DLL is called in ASP.NET it throws error -10011. I wonder why this happens only in ASP.NET.

Thanks,

Poornima

[MattP]

Hi Poornima,

I'm still curious to know if this DLL has ever worked with ASP.NET.  If it works everywhere but through this ASP application, you may want to investigate the calling ASP application, as it may be passing invalid parameters to your DLL.  Are you using the same input parameters to the DLL in both ASP and VB?  Did the DLL work from ASP before?  If the DLL can be called successfully in LabVIEW and VB, I doubt that your DLL is faulty.  As an alternate test, send the DLL intentionally bad values to try to duplicate the error in VB - this may give you a hint as to what may be going on in the ASP application.