net.wimpi.modbus.io
Class ModbusASCIITransport

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

All Implemented Interfaces:

ModbusTransport

public class ModbusASCIITransport

extends ModbusSerialTransport

Class that implements the Modbus/ASCII transport flavor.

Version:

1.2rc1 (09/11/2004)

Author:

Dieter Wimberger, John Charlton

Field Summary

static int	FRAME_END Defines a virtual number for the FRAME_END token (CR LF).
static int	FRAME_START Defines a virtual number for the FRAME START token (COLON).

Fields inherited from class net.wimpi.modbus.io.ModbusSerialTransport

m_CommPort, m_Echo

Constructor Summary

ModbusASCIITransport()
Constructs a new MobusASCIITransport instance.

Method Summary

void	close() The close method closes the serial input/output streams.
void	prepareStreams(java.io.InputStream in, java.io.OutputStream out) Prepares the input and output streams of this ModbusASCIITransport instance.
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().
ModbusResponse	readResponse() readResponse reads a response message from the slave responding to a master writeMessage request.
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 net.wimpi.modbus.io.ModbusSerialTransport

isEcho, readEcho, setCommPort, setEcho, setReceiveThreshold, setReceiveTimeout

Methods inherited from class java.lang.Object

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

Field Detail

FRAME_START

public static final int FRAME_START

Defines a virtual number for the FRAME START token (COLON).

See Also:

Constant Field Values

FRAME_END

public static final int FRAME_END

Defines a virtual number for the FRAME_END token (CR LF).

See Also:

Constant Field Values

Constructor Detail

ModbusASCIITransport

public ModbusASCIITransport()

Constructs a new MobusASCIITransport instance.

Method Detail

close

public void close()
           throws java.io.IOException

Description copied from class: ModbusSerialTransport

The close method closes the serial input/output streams.

Specified by:

close in interface ModbusTransport

Specified by:

close in class ModbusSerialTransport

Throws:

java.io.IOException - if an error occurs

writeMessage

public void writeMessage(ModbusMessage msg)
                  throws ModbusIOException

Description copied from class: ModbusSerialTransport

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

Specified by:

writeMessage in class ModbusSerialTransport

Parameters:

msg - a ModbusMessage value

Throws:

ModbusIOException - if an error occurs

readRequest

public ModbusRequest readRequest()
                          throws ModbusIOException

Description copied from class: ModbusSerialTransport

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

Specified by:

readRequest in class ModbusSerialTransport

Returns:

a ModbusRequest value

Throws:

ModbusIOException - if an error occurs

readResponse

public ModbusResponse readResponse()
                            throws ModbusIOException

Description copied from class: ModbusSerialTransport

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

Specified by:

readResponse in interface ModbusTransport

Specified by:

readResponse in class ModbusSerialTransport

Returns:

a ModbusResponse value

Throws:

ModbusIOException - if an error occurs

prepareStreams

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

Prepares the input and output streams of this ModbusASCIITransport instance. The raw input stream will be wrapped into a filtered DataInputStream.

Specified by:

prepareStreams in class ModbusSerialTransport

Parameters:

in - the input stream to be used for reading.

out - the output stream to be used for writing.

Throws:

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