Error using callib Method was not found

Hi,

I'm trying to call a function in my NIDAQ DLL, but it is not being recognized by matlab even though other functions are recognized. In general, to use calllib I understand that the syntax is: [x1,...,xN] = calllib(libname,funcname,arg1,...,argN)

What I have found is that when you purposefully remove arguments and outputs demanded by the function being called, matlab throws the error "No method with matching signature." when matlab recognizes the function in the header file. When matlab does not recognize the function in the header file, it instead returns "Method was not found"

The code I am using to test the dll is below. I have also attached a copy of the original header file saved as a text file.

Many Thanks! Thomas

%%Begin DAQ Test Code

if ~libisloaded('mynidaqmx')
    disp('Matlab: Load nicaiu.dll')
    warning('off','MATLAB:loadlibrary:TypeNotFound')

      % This is to load ni library
      loadlibrary('nicaiu.dll','nidaqmx.h','alias','mynidaqmx');

      warning('on','MATLAB:loadlibrary:TypeNotFound')
      %funclist = libfunctions('myni','-full')
      %libfunctionsview('myni')
  end

%Create task
%As defined in header file:
%int32 __CFUNC     DAQmxCreateTask          (const char taskName[], %TaskHandle %*taskHandle);
[status,taskname,taskhandle] = calllib('mynidaqmx','DAQmxCreateTask',[],uint32(1));

%Interpret error code
if status ~= 0
    bufferSize = 500;
    errorString = char(ones(1,bufferSize));
    %As defined in header file:
    %int32 __CFUNC     DAQmxGetErrorString       (int32 errorCode, char %errorString[], uInt32 bufferSize);
    [status,errorString]=calllib('mynidaqmx','DAQmxGetErrorString', ...
        status, errorString, bufferSize);

      if ~isempty(errorString)
          error(['Error ' num2str(errorCode) ': ' errorString]);
      end
  end

%Clear the task created above
%As defined in header file:
%int32 __CFUNC     DAQmxStopTask            (TaskHandle taskHandle);
[status]=calllib('mynidaqmx','DAQmxStopTask',taskhandle);
%As defined in header file:
%int32 __CFUNC     DAQmxClearTask           (TaskHandle taskHandle);
[status] = calllib('mynidaqmx','DAQmxClearTask',taskhandle);

%Matlab recognizes all functions up to this point. I can remove arugments
%and outputs from them and matlab will return the error "No method with
%matching signature."
%The function below is not recognized by matlab. I get the error "Method
%was not found." regardless of combinatorics of arguments and outputs
%As defined in header file:
%int32 __CFUNC_C   DAQmxGetSystemInfoAttribute (int32 attribute, void *value, ...);
[ status, taskarray]= calllib('mynidaqmx','DAQmxGetSystemInfoAttribute', 'DAQmx_Sys_Tasks');
DAQmxErr(status);