/***
* 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.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 @version@ (@date@)
*/
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
*/
@Override
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
@Override
public void writeData(DataOutput dout) throws IOException {
dout.writeShort(m_Reference);
dout.writeShort(m_BitCount);
}// writeData
@Override
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