s2l3.cpp

德州仪器公司的6000系列的程序示例,可以看看实现什么功能,如果需要可以继续上传,配套有电子版说明

//####################################################################
// S2L3.cpp - (Section 2, Lesson 3) RECEIVING ENTIRE MESSAGES USING
//                                  SAFEARRAYS
//            This is the RTDX Host Client for Section 2, Lesson 3
//
// This example receives integer values 1-10 from the target
//####################################################################

#import "..\..\..\..\..\cc\bin\rtdxint.dll"
#include <iostream.h>


using namespace RTDXINTLib;

int main()
{
        IRtdxExpPtr rtdx;       // holds pointer to IRtdxExp interface
        long status;            // holds status of RTDX COM API calls
        HRESULT hr;             // holds status of generic COM API calls
        VARIANT sa;             // holds pointer to SAFEARRAY
        long data;              // holds data from SAFEARRAY
        long i;                 // SAFEARRAY incrementer

        // initialize COM
        ::CoInitialize( NULL );

        // initialize VARIANT
        ::VariantInit( &sa );

        // instantiate the RTDX COM Object
        hr = rtdx.CreateInstance( __uuidof(RTDXINTLib::RtdxExp) );

        cout.setf( ios::showbase );

        if ( FAILED(hr) ) {
                cerr << hex << hr << " - Error: Instantiation failed! \n";
                return -1;
        }

        // open a channel (ochan) for reading
        status = rtdx->Open( "ochan", "R" );

        if ( status != Success ) {
                cerr << hex << status \
                     << " -  Error: Opening of a channel failed! \n";
                return -1;
        }

        // loop until we have read all of our messages
        do {
                // read a 32-bit integer message
                status = rtdx->ReadSAI4( &sa );

                // test status returned from ReadSAI4
                switch ( status ) {
                        case Success:
                                // Display data
                                cout << "\n";
                                for ( i = 0; i < (signed)sa.parray->rgsabound[0].cElements; i++) {
                                        hr = ::SafeArrayGetElement( sa.parray, &i, (long*)&data );
                                        cout << data << "\t";
                                }
                                break;
                        case Failure:
                                cerr << hex \
                                     << status \
                                     << " - Error: ReadSAI4 returned failure! \n";
                                return -1;
                        case ENoDataAvailable:
                                cout << "\n\nNo Data is currently available!\n";
                                cout << "\n\nWould you like to continue reading [y or n]?\n";
                                char option;
                                cin >> option;
                                if ( (option == 'y') || (option == 'Y') )
                                        break;
                                else
                                        return -1;
                        case EEndOfLogFile:
                                cout << "\n\nData Processing Complete!\n";
                                break;
                        default:
                                cerr << hex << status << " - Error: Unknown return code! \n";
                                return -1;
                }

        } while ( status != EEndOfLogFile );

        // close the channel
        status = rtdx->Close();

        // release the RTDX COM Object
        rtdx.Release();

        // clear Variant
        ::VariantClear( &sa );

        // uninitialize COM
        ::CoUninitialize();

         return 0;
}