1. TwinCAT ADS-DLL Java
2. TcJavaToAds
3. Zugriff per Variablenname

Zugriff per Variablenname

Das folgende Programm greift auf eine SPS-Variable zu, die keine Adresse besitzt. Der Zugriff muss deshalb per Variablenname erfolgen:

import de.beckhoff.jni.Convert;
import de.beckhoff.jni.JNIByteBuffer;
import de.beckhoff.jni.tcads.AmsAddr;
import de.beckhoff.jni.tcads.AdsCallDllFunction;

public class Main
{

 // Note that in TwinCAT 2 this has to be changed to ".PLCVar"
 private static final String PLC_VAR = "MAIN.PLCVar";

 public static void main(String[] args)
 {
    long err;
    AmsAddr addr = new AmsAddr();
    JNIByteBuffer handleBuff = new JNIByteBuffer(Integer.SIZE / Byte.SIZE);
    JNIByteBuffer symbolBuff = new JNIByteBuffer(PLC_VAR.getBytes());
    JNIByteBuffer dataBuff = new JNIByteBuffer(Integer.SIZE / Byte.SIZE);
        
    // Open communication
    AdsCallDllFunction.adsPortOpen();
    err = AdsCallDllFunction.getLocalAddress(addr);
    addr.setPort(851);

    if (err != 0) {
     System.out.println("Error: Open communication: 0x" 
         + Long.toHexString(err));
    } else {
     System.out.println("Success: Open communication!");
    }

    // Get handle by symbol name
    err = AdsCallDllFunction.adsSyncReadWriteReq(addr,
                     AdsCallDllFunction.ADSIGRP_SYM_HNDBYNAME,
                     0x0,
                     handleBuff.getUsedBytesCount(),
                     handleBuff,
                     symbolBuff.getUsedBytesCount(),
                     symbolBuff);
    if(err!=0) { 
     System.out.println("Error: Get handle: 0x" 
         + Long.toHexString(err)); 
    } else {
     System.out.println("Success: Get handle!");
    }

    // Handle: byte[] to int
    int hdlBuffToInt = Convert.ByteArrToInt(handleBuff.getByteArray());
        
    // Read value by handle
    err = AdsCallDllFunction.adsSyncReadReq(addr,
                           AdsCallDllFunction.ADSIGRP_SYM_VALBYHND,
                     hdlBuffToInt,
                     0x4,
                     dataBuff);
    if(err!=0)
    {
     System.out.println("Error: Read by handle: 0x"
                + Long.toHexString(err));
    }
    else
    {
     // Data: byte[] to int
     int intVal = Convert.ByteArrToInt(dataBuff.getByteArray());
     System.out.println("Success: PLCVar value: " + intVal);
    }

    // Release handle
    err = AdsCallDllFunction.adsSyncWriteReq(addr,
        AdsCallDllFunction.ADSIGRP_SYM_RELEASEHND,
        0,
        handleBuff.getUsedBytesCount(),
        handleBuff);

    if(err!=0) {
     System.out.println("Error: Release Handle: 0x"
         + Long.toHexString(err));
    } else {
     System.out.println("Success: Release Handle!");
    }
    
    // Close communication
    err = AdsCallDllFunction.adsPortClose();
    if(err!=0) { 
     System.out.println("Error: Close Communication: 0x" 
         + Long.toHexString(err)); 
    }

    try{
     System.in.read();
    }
    catch (Exception e){
       System.out.println("Error: Close program");
    }
 }
}

 

Beispielprogramm 'Zugriff per Variablenname' entpacken.

Um das *.jar Sample ausführen zu können, muss in der Konsole im korrekten Verzeichnis der Befehl 'java -classpath "Sample02.jar;[Pfad zu TcJavaToAds.jar] Main' ausgeführt werden (Beispielpfad: "C:TwinCAT\Ads Api\AdsToJava\*"). Dazu muss Java in den Umgebungsvariablen eingetragen sein.