//License
/***
* Java Modbus Library (jamod)
* Copyright (c) 2002-2004, jamod development team
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the author nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
***/
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.ModbusCoupler;
import net.wimpi.modbus.procimg.DigitalIn;
import net.wimpi.modbus.procimg.IllegalAddressException;
import net.wimpi.modbus.procimg.ProcessImage;
/**
* Class implementing a <tt>ReadInputDiscretesRequest</tt>.
* The implementation directly correlates with the class 1
* function <i>read input discretes (FC 2)</i>. It encapsulates
* the corresponding request message.
* <p>
* Input Discretes are understood as bits that cannot be
* manipulated (i.e. set or unset).
*
* @author Dieter Wimberger
* @version 1.2rc1 (09/11/2004)
*/
public final class ReadInputDiscretesRequest
extends ModbusRequest {
//instance attributes
private int m_Reference;
private int m_BitCount;
/**
* Constructs a new <tt>ReadInputDiscretesRequest</tt>
* instance.
*/
public ReadInputDiscretesRequest() {
super();
setFunctionCode(Modbus.READ_INPUT_DISCRETES);
//4 bytes (unit id and function code is excluded)
setDataLength(4);
}//constructor
/**
* Constructs a new <tt>ReadInputDiscretesRequest</tt>
* instance with a given reference and count of input
* discretes (i.e. bits) to be read.
* <p>
* @param ref the reference number of the register
* to read from.
* @param count the number of bits to be read.
*/
public ReadInputDiscretesRequest(int ref, int count) {
super();
setFunctionCode(Modbus.READ_INPUT_DISCRETES);
//4 bytes (unit id and function code is excluded)
setDataLength(4);
setReference(ref);
setBitCount(count);
}//constructor
/*
public ModbusResponse getResponse() {
ReadInputDiscretesResponse response =
new ReadInputDiscretesResponse(getBitCount());
response.setHeadless(isHeadless());
return response;
}//getResponse
*/
public ModbusResponse createResponse() {
ReadInputDiscretesResponse response = null;
DigitalIn[] dins = null;
//1. get process image
ProcessImage procimg = ModbusCoupler.getReference().getProcessImage();
//2. get inputdiscretes range
try {
dins = procimg.getDigitalInRange(this.getReference(), this.getBitCount());
} catch (IllegalAddressException iaex) {
return createExceptionResponse(Modbus.ILLEGAL_ADDRESS_EXCEPTION);
}
response = new ReadInputDiscretesResponse(dins.length);
//transfer header data
if (!isHeadless()) {
response.setTransactionID(this.getTransactionID());
response.setProtocolID(this.getProtocolID());
} else {
response.setHeadless();
}
response.setUnitID(this.getUnitID());
response.setFunctionCode(this.getFunctionCode());
for (int i = 0; i < dins.length; i++) {
response.setDiscreteStatus(i, dins[i].isSet());
}
return response;
}//createResponse
/**
* Sets the reference of the register to start reading
* from with this <tt>ReadInputDiscretesRequest</tt>.
* <p>
* @param ref the reference of the register
* to start reading from.
*/
public void setReference(int ref) {
m_Reference = ref;
//setChanged(true);
}//setReference
/**
* Returns the reference of the register to to start
* reading from with this
* <tt>ReadInputDiscretesRequest</tt>.
* <p>
* @return the reference of the register
* to start reading from as <tt>int</tt>.
*/
public int getReference() {
return m_Reference;
}//getReference
/**
* Sets the number of bits (i.e. input discretes) to be
* read with this <tt>ReadInputDiscretesRequest</tt>.
* <p>
* @param count the number of bits to be read.
*/
public void setBitCount(int count) {
//assert <=2000
m_BitCount = count;
//setChanged(true);
}//setBitCount
/**
* Returns the number of bits (i.e. input discretes)
* to be read with this
* <tt>ReadInputDiscretesRequest</tt>.
* <p>
* @return the number of bits to be read.
*/
public int getBitCount() {
return m_BitCount;
}//getBitCount
public void writeData(DataOutput dout)
throws IOException {
dout.writeShort(m_Reference);
dout.writeShort(m_BitCount);
}//writeData
public void readData(DataInput din)
throws IOException {
m_Reference = din.readUnsignedShort();
m_BitCount = din.readUnsignedShort();
}//readData
/*
protected void assembleData() throws IOException {
m_DataOut.writeShort(m_Reference);
m_DataOut.writeShort(m_BitCount);
}//assembleData
public void readData(DataInputStream in) throws IOException, EOFException {
m_Reference = in.readUnsignedShort();
m_BitCount = in.readUnsignedShort();
}//readData
*/
}//class ReadInputDiscretesRequest