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Using IVI with Visual C++

•

Set the Reading Timeout/Display the Reading

Create a variable to represent the reading and make a reading with a timeout of 1

second (1000 milliseconds).

1 Type

double reading = dmm->Measurement->Read(1000);

2 To display the reading, use printf. Type

wprintf(L“Reading: %g\n”, reading);

Error Checking

To catch errors in the code, activate error checking.

1 Surround the preceding statements with a try block. Add the following lines as

shown in the illustration above:

try {

}

2 Process errors in a catch block. Type

catch (_com_error e) {

wprintf(L“Error: %s”, e.ErrorMessage());

}

Close the Session

To close out the instance of the driver and free resources, type

dmm->Close();

The final code should look like the following:

#include "stdafx.h"

#import "IviDriverTypeLib.dll" no_namespace

#import "IviDmmTypeLib.dll" no_namespace

#import "GlobMgr.dll" no_namespace

#import "Agilent34401.dll" no_namespace

int IVI_Demo()

{

HRESULT hr;

hr = CoInitialize(NULL);

if(FAILED(hr))

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HP Drive Manual do Utilizador Página 21