Access an array in the PLC

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An array, located in the PLC, is to be read by means of a read command. The variable is addressed here by its handle. The length of the whole array is provided as the length for the function AdsSyncReadReq(). The address of the first array element is given as variable.

#include <iostream.h>
#include <windows.h>
#include <conio.h>

// ADS headers for TwinCAT 3
#include "C:\TwinCAT\AdsApi\TcAdsDll\Include\TcAdsDef.h"
#include "C:\TwinCAT\AdsApi\TcAdsDll\Include\TcAdsAPI.h"

void main()
{
 long     nErr, nPort;
 AmsAddr Addr;
 PAmsAddr pAddr = &Addr;
 unsigned long lHdlVar;
 int     nIndex;
 short     Data[10];
 char     szVar []={"MAIN.PLCVar"};

 // Open communication port on the ADS router
 nPort = AdsPortOpen();
 nErr = AdsGetLocalAddress(pAddr);
 if (nErr) cerr << "Error: AdsGetLocalAddress: " << nErr << '\n';
 
 // Select Port: TwinCAT 3 PLC1 = 851
 pAddr->port = 851;

 // Fetch handle for the PLC variable 
 nErr = AdsSyncReadWriteReq(pAddr, ADSIGRP_SYM_HNDBYNAME, 0x0, sizeof(lHdlVar), &lHdlVar, sizeof(szVar), szVar);
 if (nErr) cerr << "Error: AdsSyncReadWriteReq: " << nErr << '\n'; 
 // Read values of the PLC variables (by handle)
 nErr = AdsSyncReadReq(pAddr, ADSIGRP_SYM_VALBYHND, lHdlVar, sizeof(Data), &Data[0]);
 if (nErr)
 cerr << "Error: AdsSyncReadReq: " << nErr << '\n'; 
 else
 {
 for (nIndex = 0; nIndex < 10; nIndex++)
 cout << "Data[" << nIndex << "]: " << Data[nIndex] << '\n';
 }
 cout.flush();
 getch();
 // Close communication port
 nErr = AdsPortClose(); 
 if (nErr) cerr << "Error: AdsPortClose: " << nErr << '\n';
}