This is a library built around moka7 created by Dave Nardella. Moka7 is is the Java port of Snap7 Client. It’s a pure Java implementation of the S7Protocol used to communicate with S7 PLCs.
Package can be installed via maven by adding the following to your pom.xml:
<dependency>
<groupId>si.trina</groupId>
<artifactId>moka7-live</artifactId>
<version>0.0.5</version>
</dependency>
1. Create classes that implement interface PLCListener
2. Create PLC class instances for every PLC you wish to receive bit changes / read integers, bits from
import si.trina.moka7.live.PLC;
/*
args:
** name of PLC
** IP of PLC
** byte array with length of db PLC->PC
** byte array with length of PC->PLC
** db (DataBase) number PLC->PC
** db (DataBase) number PC->PLC
** array of addresses of booleans to listen to changes to
*/
PLC plc1 = new PLC("Test PLC1","10.10.21.10",new byte[32],new byte[36],112,114,new double[]{0.1,0.2});
PLC plc2 = new PLC("Test PLC2", "10.10.22.10",new byte[18],new byte[22],45,44,new double[]{0.1,0.2,0.3});
3. Add classes that implement interface PLCListener to PLC's ArrayList<PLCListener> listener array
PLCListenerImplementation myListener = new PLCListenerImplementation();
plc1.listeners.add(myListener);
plc2.listeners.add(myListener);
4. Start a thread for each PLC instance
Thread t1 = new Thread(plc1).start();
Thread t2 = new Thread(plc2).start();
5. Receive bit changes from bits at addresses from last argument of PLC constructor
import si.trina.moka7.live.PLCListener;
public class PLCListenerImplementation implements PLCListener {
@Override
public void PLCBitChanged(int address, int pos, boolean val, String plcName) {
switch (address) {
case 0:
switch (pos) {
case 1:
System.out.println("Bit at address 0.1 of PLC " + plcName + " changed to: " + val);
}
}
}
}
6. Write shorts/integers to DB
/*
args:
** database to write to: from plc = true, from pc = false
** address to write to
** short/integer to write to db
*/
plc1.putInt(false, 12, (short)3);
plc1.putDInt(false, 12, 3);
7. Read shorts/integers from DB
try {
short aShort = plc1.getInt(true, 8); // 2 bytes
int anInteger = plc1.getDInt(true, 8); // 4 bytes
} catch (Exception e) {
e.printStackTrace();
}