WriteCoilResponse.java

/***
 * Copyright 2002-2010 jamod development team
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ***/

package net.wimpi.modbus.msg;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import net.wimpi.modbus.Modbus;

/**
 * Class implementing a <tt>WriteCoilResponse</tt>.
 * The implementation directly correlates with the class 0
 * function <i>write coil (FC 5)</i>. It
 * encapsulates the corresponding response message.
 *
 * @author Dieter Wimberger
 * @version @version@ (@date@)
 */
public final class WriteCoilResponse extends ModbusResponse {

    // instance attributes
    private boolean m_Coil = false;
    private int m_Reference;

    /**
     * Constructs a new <tt>WriteCoilResponse</tt>
     * instance.
     */
    public WriteCoilResponse() {
        super();
        setFunctionCode(Modbus.WRITE_COIL);
        setDataLength(4);
    }// constructor

    /**
     * Constructs a new <tt>WriteCoilResponse</tt>
     * instance.
     *
     * @param reference the offset were writing was started from.
     * @param b the state of the coil; true set, false reset.
     */
    public WriteCoilResponse(int reference, boolean b) {
        super();
        setFunctionCode(Modbus.WRITE_COIL);
        setDataLength(4);
        setReference(reference);
        setCoil(b);
    }// constructor

    /**
     * Sets the state that has been returned
     * in the raw response.
     * <p>
     *
     * @param b true if the coil should be set of
     *            false if it should be unset.
     */
    private void setCoil(boolean b) {
        m_Coil = b;
    }// setCoil

    /**
     * Gets the state that has been returned
     * in this <tt>WriteCoilRequest</tt>.
     * <p>
     *
     * @return true if the coil is set, false if unset.
     */
    public boolean getCoil() {
        return m_Coil;
    }// getCoil

    /**
     * Returns the reference of the register of the coil
     * that has been written to with the request.
     * <p>
     *
     * @return the reference of the coil's register.
     */
    public int getReference() {
        return m_Reference;
    }// getReference

    /**
     * Sets the reference of the register of the coil
     * that has been written to with the request.
     * <p>
     *
     * @param ref the reference of the coil's register.
     */
    private void setReference(int ref) {
        m_Reference = ref;
        // setChanged(true);
    }// setReference

    @Override
    public void writeData(DataOutput dout) throws IOException {
        dout.writeShort(getReference());
        if (getCoil()) {
            dout.write(Modbus.COIL_ON_BYTES, 0, 2);
        } else {
            dout.write(Modbus.COIL_OFF_BYTES, 0, 2);
        }
    }// writeData

    @Override
    public void readData(DataInput din) throws IOException {
        setReference(din.readUnsignedShort());

        byte[] data = new byte[2];
        for (int k = 0; k < 2; k++) {
            data[k] = din.readByte();
        }
        // set toggle
        if (data[0] == Modbus.COIL_ON) {
            setCoil(true);
        } else {
            setCoil(false);
        }

        // update data length
        setDataLength(4);
    }// readData

}// class WriteCoilResponse