net.wimpi.modbus.io
Class ModbusSerialTransport

java.lang.Object
  net.wimpi.modbus.io.ModbusSerialTransport

All Implemented Interfaces:

ModbusTransport

Direct Known Subclasses:

ModbusASCIITransport, ModbusBINTransport, ModbusRTUTransport

public abstract class ModbusSerialTransport

extends java.lang.Object

implements ModbusTransport

Abstract base class for serial ModbusTransport implementations.

Version:

1.2rc1 (09/11/2004)

Author:

Dieter Wimberger, John Charlton

Field Summary

protected javax.comm.CommPort	m_CommPort
protected boolean	m_Echo

Constructor Summary

ModbusSerialTransport()

Method Summary

abstract void	close() The close method closes the serial input/output streams.
boolean	isEcho() isEcho method returns the output echo state.
abstract void	prepareStreams(java.io.InputStream in, java.io.OutputStream out) prepareStreams prepares the input and output streams of this ModbusSerialTransport instance.
void	readEcho(int len) Reads the own message echo produced in RS485 Echo Mode within the given time frame.
abstract ModbusRequest	readRequest() The readRequest method listens continuously on the serial input stream for master request messages and replies if the request slave ID matches its own set in ModbusCoupler.getUnitID().
abstract ModbusResponse	readResponse() readResponse reads a response message from the slave responding to a master writeMessage request.
void	setCommPort(javax.comm.CommPort cp) setCommPort sets the comm port member and prepares the input and output streams to be used for reading from and writing to.
void	setEcho(boolean b) setEcho method sets the output echo state.
void	setReceiveThreshold(int th) Describe setReceiveThreshold method here.
void	setReceiveTimeout(int ms) Describe setReceiveTimeout method here.
abstract void	writeMessage(ModbusMessage msg) The writeMessage method writes a modbus serial message to its serial output stream to a specified slave unit ID.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_CommPort

protected javax.comm.CommPort m_CommPort

m_Echo

protected boolean m_Echo

Constructor Detail

ModbusSerialTransport

public ModbusSerialTransport()

Method Detail

prepareStreams

public abstract void prepareStreams(java.io.InputStream in,
                                    java.io.OutputStream out)
                             throws java.io.IOException

prepareStreams prepares the input and output streams of this ModbusSerialTransport instance.

Parameters:

in - the input stream to be read from.

out - the output stream to write to.

Throws:

java.io.IOException - if an I\O error occurs.

readResponse

public abstract ModbusResponse readResponse()
                                     throws ModbusIOException

readResponse reads a response message from the slave responding to a master writeMessage request.

Specified by:

readResponse in interface ModbusTransport

Returns:

a ModbusResponse value

Throws:

ModbusIOException - if an error occurs

readRequest

public abstract ModbusRequest readRequest()
                                   throws ModbusIOException

The readRequest method listens continuously on the serial input stream for master request messages and replies if the request slave ID matches its own set in ModbusCoupler.getUnitID().

Specified by:

readRequest in interface ModbusTransport

Returns:

a ModbusRequest value

Throws:

ModbusIOException - if an error occurs

writeMessage

public abstract void writeMessage(ModbusMessage msg)
                           throws ModbusIOException

The writeMessage method writes a modbus serial message to its serial output stream to a specified slave unit ID.

Specified by:

writeMessage in interface ModbusTransport

Parameters:

msg - a ModbusMessage value

Throws:

ModbusIOException - if an error occurs

close

public abstract void close()
                    throws java.io.IOException

The close method closes the serial input/output streams.

Specified by:

close in interface ModbusTransport

Throws:

java.io.IOException - if an error occurs

setCommPort

public void setCommPort(javax.comm.CommPort cp)
                 throws java.io.IOException

setCommPort sets the comm port member and prepares the input and output streams to be used for reading from and writing to.

Parameters:

cp - the comm port to read from/write to.

Throws:

java.io.IOException - if an I/O related error occurs.

isEcho

public boolean isEcho()

isEcho method returns the output echo state.

Returns:

a boolean value

setEcho

public void setEcho(boolean b)

setEcho method sets the output echo state.

Parameters:

b - a boolean value

setReceiveThreshold

public void setReceiveThreshold(int th)

Describe setReceiveThreshold method here.

Parameters:

th - an int value

setReceiveTimeout

public void setReceiveTimeout(int ms)

Describe setReceiveTimeout method here.

Parameters:

ms - an int value

readEcho

public void readEcho(int len)
              throws java.io.IOException

Reads the own message echo produced in RS485 Echo Mode within the given time frame.

Parameters:

len - is the length of the echo to read. Timeout will occur if the echo is not received in the time specified in the SerialConnection.

Throws:

java.io.IOException - if a I/O error occurred.