HP Drive manual Using IVI with Visual C++

Note:

You are now ready to write the program to control the simulated instrument.

This creates a smart pointer that provides easy access to the COM object.

“$(VXIPNPPATH)VisaCom”

Note: These steps need only be done once for each computer you use. All subsequent Visual Studio projects will continue to use these settings and will be able to locate your IVI-COM drivers.

6 Click OK

7 To import the type libraries, type the following statements following the header file reference:

#import “IviDriverTypeLib.dll” no_namespace #import “IviDmmTypeLib.dll” no_namespace #import “GlobMgr.dll” no_namespace #import “Agilent34401.dll” no_namespace

Note: The import statements access the driver type libraries used by the Agilent 34401 DMM. The no_namespace attribute allows the code to access the interfaces in the typelibraries from the global namespace.

Initialize COM

1 To initialize the COM library, type the following lines after the { following the int statement:

HRESULT hr;

hr = CoInitialize(NULL); IF(FAILED(hr))

exit(1);

Note: Including error handling in your programs is good practice. This code checks for errors in your program.

2 To close the COM library before exiting, type the following line at the end of your code, right before the return line:

CoUninitialize();

Create an Instance of the Driver

To create an instance of the driver, type IIviDmmPtr dmm(__uuidof(Agilent34401));

•

•

Using IVI with Visual C++ • 19

•

•

•