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Incorrect header for niHSDIO_HWC_FetchSampleErrors?

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Hi.  Most of my test program is working well, but I seem to be having a problem with the niHSDIO_HWC_FetchSampleErrors prototype. 

 

Here is the function prototype from the niHSDIO.h include file:

  ViStatus _VI_FUNC niHSDIO_HWC_FetchSampleErrors(
     ViSession vi,
     ViInt32 numSampleErrorsToRead,
     ViInt32 maxTimeMilliseconds,
     ViInt32* numSampleErrorsRead,
     ViReal64 sampleNumber[],
     ViUInt32 errorBits[],
     ViInt32 errorRepeatCount[],
     ViUInt32* reserved1,
     ViUInt32* reserved2);
  

Here is the exception detail that I captured:

  Exception caught
  Detail:  [Error -1074135024] Windows Error 0xBFFA0010
  DLL Description:  Invalid value for parameter or property.

  Parameter 8 out of range, or error occurred while setting Parameter 8.

I believe this is referring to either reserved1 or reserved2.  I am passing pointers to a unsigned longs initialized to "0" in both cases.  What should be here?

 

Also,  the help file in LabView 8.5 has does not have a correct description for this function (it is missing a parameter):

  ViStatus niHSDIO_HWC_FetchSampleErrors (

     ViSession vi,

     ViInt32* numSampleErrorsToRead,

     ViInt32 maxTimeMilliseconds,

     ViReal64[] sampleNumber,

     ViUInt32[] errorBits,

     ViInt32[] errorRepeatCount,

     ViUInt32* reserved1,

     ViUInt32* reserved2);

(when I tried to use the help file's definition, the system complained about missing 4 bytes of passing arguments so I assume the niHSDIO.h file's reference is more accurate.)

 

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My colleague found that all of the example "C" code using this function passes NULL to the "reserved" parameters (instead of a pointer to ViUint32 variables). When NULL is passed to the 2 reserved parameters instead of a pointer, then the code runs without raising an exception. (And the 3 arrays "sampleNumber", "errorBits", and "errorRepeatCount" do return meaningful data...)

 

Perhaps I don't understand C as well as I should, but I would think there would be another way to declare the two reserved parameters in the include file so that it is more clear that NULL must be passed...

 

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I think that this is one of the cases where the function prototype was developed with extra inputs/outputs that were taken out at some point, or this function was created with scalable functionality. I think that if you pass in NULL for those two inputs to the function it should work properly. I have a feeling that you were getting an out of range error because it wasn't actually expecting a real value as an input. Give that a try and let us know the results.

 

Oops I guess I posted too late...

Message Edited by Chris W. on 01-29-2009 05:48 PM
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