/***
* 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;
import net.wimpi.modbus.util.BitVector;
/**
* Class implementing a <tt>ReadInputDiscretesResponse</tt>.
* The implementation directly correlates with the class 1
* function <i>read input discretes (FC 2)</i>. It encapsulates
* the corresponding response message.
* <p>
* Input Discretes are understood as bits that cannot be
* manipulated (i.e. set or unset).
*
* @author Dieter Wimberger
* @version @version@ (@date@)
*/
public final class ReadInputDiscretesResponse extends ModbusResponse {
// instance attributes
private int m_BitCount;
private BitVector m_Discretes;
/**
* Constructs a new <tt>ReadInputDiscretesResponse</tt>
* instance.
*/
public ReadInputDiscretesResponse() {
super();
setFunctionCode(Modbus.READ_INPUT_DISCRETES);
}// constructor
/**
* Constructs a new <tt>ReadInputDiscretesResponse</tt>
* instance with a given count of input discretes
* (i.e. bits).
* <b>
*
* @param count the number of bits to be read.
*/
public ReadInputDiscretesResponse(int count) {
super();
setBitCount(count);
}// constructor
/**
* Returns the number of bits (i.e. input discretes)
* read with the request.
* <p>
*
* @return the number of bits that have been read.
*/
public int getBitCount() {
return m_BitCount;
}// getBitCount
/**
* Sets the number of bits in this response.
*
* @param count the number of response bits as int.
*/
public void setBitCount(int count) {
m_BitCount = count;
m_Discretes = new BitVector(count);
// set correct length, without counting unitid and fc
setDataLength(m_Discretes.byteSize() + 1);
}// setBitCount
/**
* Returns the <tt>BitVector</tt> that stores
* the collection of bits that have been read.
* <p>
*
* @return the <tt>BitVector</tt> holding the
* bits that have been read.
*/
public BitVector getDiscretes() {
return m_Discretes;
}// getDiscretes
/**
* Convenience method that returns the state
* of the bit at the given index.
* <p>
*
* @param index the index of the input discrete
* for which the status should be returned.
*
* @return true if set, false otherwise.
*
* @throws IndexOutOfBoundsException if the
* index is out of bounds
*/
public boolean getDiscreteStatus(int index) throws IndexOutOfBoundsException {
return m_Discretes.getBit(index);
}// getDiscreteStatus
/**
* Sets the status of the given input discrete.
*
* @param index the index of the input discrete to be set.
* @param b true if to be set, false if to be reset.
* @throws IndexOutOfBoundsException if the given index exceeds bounds.
*/
public void setDiscreteStatus(int index, boolean b) throws IndexOutOfBoundsException {
m_Discretes.setBit(index, b);
}// setDiscreteStatus
@Override
public void writeData(DataOutput dout) throws IOException {
dout.writeByte(m_Discretes.byteSize());
dout.write(m_Discretes.getBytes(), 0, m_Discretes.byteSize());
}// writeData
@Override
public void readData(DataInput din) throws IOException {
int count = din.readUnsignedByte();
byte[] data = new byte[count];
for (int k = 0; k < count; k++) {
data[k] = din.readByte();
}
// decode bytes into bitvector
m_Discretes = BitVector.createBitVector(data);
// update data length
setDataLength(count + 1);
}// readData
}// class ReadInputDiscretesResponse