singleton pattern, readfloat and readboolean are done

src/main/java/ch/hevs/isi/field/ModbusAccessor.java

@@ -0,0 +1,107 @@
+package ch.hevs.isi.field;
+
+import com.serotonin.modbus4j.ModbusFactory;
+import com.serotonin.modbus4j.ModbusMaster;
+import com.serotonin.modbus4j.code.DataType;
+import com.serotonin.modbus4j.exception.ErrorResponseException;
+import com.serotonin.modbus4j.exception.ModbusTransportException;
+import com.serotonin.modbus4j.ip.IpParameters;
+import com.serotonin.modbus4j.ip.tcp.TcpMaster;
+import com.serotonin.modbus4j.locator.BaseLocator;
+
+public class ModbusAccessor {
+
+    private static ModbusAccessor mySelf = null;
+    private ModbusMaster master = null;
+
+    /**
+     * private constructor
+     * */
+    private ModbusAccessor(){
+
+    }
+
+    /**
+     * static method to create a singleton pattern of the class
+     * checks if an instance of the class is already made
+     * if not, it creates an instance of the class ModbusAccessor
+     * @return instance of ModbusAccessor
+     */
+    public static ModbusAccessor getMySelf(){
+        if (mySelf == null){
+            mySelf = new ModbusAccessor();
+        }
+        return mySelf;
+    }
+
+    public void connect(String ipAddress, int port){
+        ModbusFactory MF = new ModbusFactory();
+        IpParameters IpParams = new IpParameters();
+
+        this.master = MF.createTcpMaster(IpParams, true);
+        /**
+         * TODO finish connect()
+         */
+    }
+
+    /**
+     * methods to write in the modbus registers
+     */
+
+    /**
+     * method to write a boolean value on the modbus address
+     * @param address the address of the modbus register
+     * @param value the value to write in the register
+     */
+    public void writeBoolean (int address, boolean value){
+        /**
+         * TODO writeBoolean()
+         */
+    }
+
+    /**
+     * method to write a float value on the modbus address
+     * @param address the address of the modbus register
+     * @param value the value to write in the register
+     */
+    public void writeFloat (int address, float value){
+        /**
+         * TODO writeFloat()
+         */
+    }
+
+    /**
+     * methods to read from the modbus registers
+     */
+
+    /**
+     * method to read a boolean value in the correct modbus register
+     * get the coil status of the register.
+     * @param register address of register
+     * @return  boolean value of the desired register
+     */
+    public boolean readBoolean(int register) throws ModbusTransportException, ErrorResponseException {
+        /**
+         * first parameter = slaveID = always 1 because we only have one
+         * second parameter = register address ==> it is named offset because it starts with 0 and goes to the desired address
+         */
+        boolean booleanValue = this.master.getValue(BaseLocator.coilStatus(1,register));
+       return booleanValue;
+    }
+
+    /**
+     * method to read a boolean value in the correct modbus register
+     * get the value from the holding register
+     * @param register address of the register
+     * @return float value of the desired register
+     */
+    public float readFloat(int register){
+        /**
+         * first parameter = slaveID = always 1 because we only have one
+         * second parameter = register address ==> it is named offset because it starts with 0 and goes to the desired address
+         * thrid parameter = DataType of the value. The max value is 3 Byte Float, but the class DataType has only 2 or 4 byte
+         */
+       float floatValue = this.master.getValue(BaseLocator.holdingRegister(1,register, DataType.FOUR_BYTE_FLOAT);
+        return floatValue;
+    }
+}