jcontrol.comm
Class UART

java.lang.Object
  jcontrol.comm.UART

All Implemented Interfaces:

BasicInputStream, BasicOutputStream

Direct Known Subclasses:

RS232

public class UART
extends Object
implements BasicInputStream, BasicOutputStream

Access to UART-Ports of Device

Field Summary

static int	PARAMS_ECHO Enables echo for received characters.
static int	PARAMS_FLOWCONTROL_RTSCTS Enables hardware handshaking using RTS and CTS lines.
static int	PARAMS_FLOWCONTROL_XONXOFF Enables software handshaking using XON and XOFF symbols.
static int	PARAMS_MULTIDROP_ADDRESS Enables address multidrop mode.
static int	PARAMS_MULTIDROP_DATA Enables data multidrop mode.
static int	PARAMS_PARITY_EVEN Enables even parity "8E1" (default: no parity "8N1").
static int	PARAMS_PARITY_MASK There can only exists one of the 4 parity-types PARAMS_PARITY_EVEN, PARAMS_PARITY_ODD, PARAMS_MULTIDROP_ADDRESS and PARAMS_MULTIDROP_DATA.
static int	PARAMS_PARITY_ODD Enables odd parity "8O1" (default: no parity "8N1").
static int	PORT_RS232_0 port declaration: rs232_0 existing on all JControl-Devices
static int	PORT_RS232_1 port declaration: rs232_1 existing on JControl/BFT-Device
static int	PORT_RS232_2 port declaration: rs232_2 for future purposes
static int	PORT_RS232_3 port declaration: rs232_3 for future purposes
static int	PORT_RS422_0 port declaration: rs422_0 existing on JControl/BFT-Device
static int	PORT_RS422_1 port declaration: rs422_1 for future purposes
static int	PORT_RS422_2 port declaration: rs422_2 for future purposes
static int	PORT_RS422_3 port declaration: rs422_3 for future purposes

Constructor Summary

UART(int port)
Constructor

Method Summary

int	available() Returns the number of available characters in the input buffer.
void	close() Closes the stream, further writes and reads are not possible, the RS232 hardware will be turned off.
int	errorCode() Returns the current Error-Code.
void	flush() flush unsent bytes (if exists)
int	getBaudrate() Gets the current Baudrate of Device
int	getParams() Gets some serail port feature parameters.
void	mark(int readlimit) NOTE: not supported!
boolean	markSupported() NOTE: not supported!
int	read() Reads the next available character from the input buffer.
int	read(byte[] b) Reads some number of bytes from the input stream and stores them into the buffer array b.
int	read(byte[] buffer, int startindex, int length) Reads a byte array from the input buffer.
void	reset() NOTE: not supported!
void	setBaudrate(int baudrate) Sets the serial port baudrate.
void	setCharacterGuardTime(int bits) Sets the character guard time, i.e. the time to wait between sending two characters over the serial port.
void	setParams(int params) Sets some serial port feature parameters.
int	skip(int n) skips n bytes of reading characters
void	write(byte[] b) Writes b.length bytes from the specified byte array to this output stream.
void	write(byte[] buffer, int startindex, int length) Writes a block of bytes to the serial port -- as it is.
void	write(int b) Writes one byte to the serial port.

Methods inherited from class java.lang.Object

clone, equals, getClass, notifyAll, toString, wait

Field Detail

PARAMS_PARITY_MASK

public static final int PARAMS_PARITY_MASK

There can only exists one of the 4 parity-types PARAMS_PARITY_EVEN, PARAMS_PARITY_ODD, PARAMS_MULTIDROP_ADDRESS and PARAMS_MULTIDROP_DATA. Mask the params by PARAMS_PARITY_MASK to get the int-value of parity type.

See Also:

Constant Field Values

PARAMS_PARITY_EVEN

public static final int PARAMS_PARITY_EVEN

Enables even parity "8E1" (default: no parity "8N1"). Do not use in conjunction with PARITY_ODD,PARAMS_MULTIDROP_ADDRESS,PARAMS_MULTIDROP_DATA.

See Also:

setParams(int), #PARITY_ODD, PARAMS_MULTIDROP_ADDRESS, PARAMS_MULTIDROP_DATA, Constant Field Values

PARAMS_PARITY_ODD

public static final int PARAMS_PARITY_ODD

Enables odd parity "8O1" (default: no parity "8N1"). Do not use in conjunction with PARITY_EVEN,PARAMS_MULTIDROP_ADDRESS,PARAMS_MULTIDROP_DATA.

See Also:

setParams(int), #PARITY_EVEN, PARAMS_MULTIDROP_ADDRESS, PARAMS_MULTIDROP_DATA, Constant Field Values

PARAMS_MULTIDROP_ADDRESS

public static final int PARAMS_MULTIDROP_ADDRESS

Enables address multidrop mode. Do not use in conjunction with PARAMS_PARITY_EVEN,PARAMS_PARITY_ODD,PARAMS_MULTIDROP_DATA. In multidrop mode during receiving the character type (data/address) is ignored and can't identified.

See Also:

setParams(int), #PARITY_EVEN, #PARITY_ODD, PARAMS_MULTIDROP_DATA, Constant Field Values

PARAMS_MULTIDROP_DATA

public static final int PARAMS_MULTIDROP_DATA

Enables data multidrop mode. Do not use in conjunction with PARAMS_PARITY_EVEN,PARAMS_PARITY_ODD,PARAMS_MULTIDROP_ADDRESS. In multidrop mode during receiving the character type (data/address) is ignored and can't identified.

See Also:

setParams(int), #PARITY_EVEN, #PARITY_ODD, PARAMS_MULTIDROP_ADDRESS, Constant Field Values

PARAMS_ECHO

public static final int PARAMS_ECHO

Enables echo for received characters.

See Also:

setParams(int), Constant Field Values

PARAMS_FLOWCONTROL_XONXOFF

public static final int PARAMS_FLOWCONTROL_XONXOFF

Enables software handshaking using XON and XOFF symbols. Use only for ASCII based communication. Do not use in conjunction with FLOWCONTROL_RTSCTS.

See Also:

setParams(int), Constant Field Values

PARAMS_FLOWCONTROL_RTSCTS

public static final int PARAMS_FLOWCONTROL_RTSCTS

Enables hardware handshaking using RTS and CTS lines. May be ignored on some devices. Do not use in conjunction with FLOWCONTROL_XONXOFF.

See Also:

setParams(int), Constant Field Values

PORT_RS232_0

public static final int PORT_RS232_0

port declaration: rs232_0

existing on all JControl-Devices

See Also:

Constant Field Values

PORT_RS232_1

public static final int PORT_RS232_1

port declaration: rs232_1

existing on JControl/BFT-Device

See Also:

Constant Field Values

PORT_RS232_2

public static final int PORT_RS232_2

port declaration: rs232_2

for future purposes

See Also:

Constant Field Values

PORT_RS232_3

public static final int PORT_RS232_3

port declaration: rs232_3

for future purposes

See Also:

Constant Field Values

PORT_RS422_0

public static final int PORT_RS422_0

port declaration: rs422_0

existing on JControl/BFT-Device

See Also:

Constant Field Values

PORT_RS422_1

public static final int PORT_RS422_1

port declaration: rs422_1

for future purposes

See Also:

Constant Field Values

PORT_RS422_2

public static final int PORT_RS422_2

port declaration: rs422_2

for future purposes

See Also:

Constant Field Values

PORT_RS422_3

public static final int PORT_RS422_3

port declaration: rs422_3

for future purposes

See Also:

Constant Field Values

Constructor Detail

UART

public UART(int port)
     throws IOException

Constructor

Throws:

IOException

Method Detail

available

public int available()
              throws IOException

Returns the number of available characters in the input buffer.

Specified by:

available in interface BasicInputStream

Returns:

the number of available chars

Throws:

IOException - if an error occurs

read

public int read()
         throws IOException

Reads the next available character from the input buffer. This method blocks until a character is available.

Specified by:

read in interface BasicInputStream

Returns:

the read out character

Throws:

IOException - if an error occurs

See Also:

available()

read

public int read(byte[] buffer,
                int startindex,
                int length)
         throws IOException

Reads a byte array from the input buffer.

Specified by:

read in interface BasicInputStream

Parameters:

buffer - the byte array to fill

index - the index to start filling the array

length - number of bytes to read; the array is filled from index to index+length-1

Returns:

the number of bytes read

Throws:

IOException - if an error occurs

See Also:

InputStream.read()

read

public int read(byte[] b)
         throws IOException

Description copied from interface: BasicInputStream

Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

If b is null, a NullPointerException is thrown. If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected.

If the first byte cannot be read for any reason other than end of file, then an IOException is thrown. In particular, an IOException is thrown if the input stream has been closed.

The read(b) method for class InputStream has the same effect as:

 read(b, 0, b.length) 

Specified by:

read in interface BasicInputStream

Parameters:

b - the buffer into which the data is read.

Returns:

the total number of bytes read into the buffer, or -1 is there is no more data because the end of the stream has been reached.

Throws:

IOException - if an I/O error occurs.

See Also:

read(byte[] buffer, int startindex, int length)

write

public void write(int b)
           throws IOException

Writes one byte to the serial port. The unicode character is trucated to one byte.

Specified by:

write in interface BasicOutputStream

Parameters:

data - the byte to send (coded in a short allowing a range 0 ... 255)

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.

See Also:

write(byte[],int,int)

write

public void write(byte[] buffer,
                  int startindex,
                  int length)
           throws IOException

Writes a block of bytes to the serial port -- as it is.

Specified by:

write in interface BasicOutputStream

Parameters:

buffer - the byte array to send

index - the index to start reading the array

length - number of bytes to write; the array is read from index to index+length-1

Throws:

IOException - if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed.

write

public void write(byte[] b)
           throws IOException

Description copied from interface: BasicOutputStream

Writes b.length bytes from the specified byte array to this output stream. The general contract for write(b) is that it should have exactly the same effect as the call write(b, 0, b.length).

Specified by:

write in interface BasicOutputStream

Parameters:

b - the data.

Throws:

IOException - if an I/O error occurs.

See Also:

write(byte[] buffer, int startindex, int length)

close

public void close()

Closes the stream, further writes and reads are not possible, the RS232 hardware will be turned off.

Specified by:

close in interface BasicInputStream

Specified by:

close in interface BasicOutputStream

setBaudrate

public void setBaudrate(int baudrate)

Sets the serial port baudrate. This is controller dependent.

Parameters:

baudrate - the baudrate to use, possible values are:

Baudrates for JControl/Gimlin(16Bit)
Baudrate	Parameter
600	600
1200	1200
2400	2400
4800	4800
9600	9600
19.200	19200
31.250	31250
38.400	38
62.500	62
125.000	125
250.000	250

Baudrates for JControl/Gimlin (32Bit)
Baudrate	Parameter
300	300
600	600
1200	1200
2400	2400
4800	4800
9600	9600
19.200	19200
31.250	31250
62.500	62500
125.000	125000
250.000	250000

Defaults to the value specified by the system property "rs232.baudrate".

getBaudrate

public int getBaudrate()

Gets the current Baudrate of Device

Returns:

baudrate

setParams

public void setParams(int params)

Sets some serial port feature parameters. Defaults to the value specified by the system property "rs232.params".

Parameters:

params - bitmask with parameters

See Also:

#PARITY_EVEN, #PARITY_ODD, #ECHO, #FLOWCONTROL_XONXOFF, #FLOWCONTROL_RTSCTS

getParams

public int getParams()

Gets some serail port feature parameters.

Returns:

errorCode

public int errorCode()

Returns the current Error-Code. If an error occurs (IOException) the cause may be found here. The Error-Code is cleared after readout (if not, the error remains active and every RS232 access will throw another IOException). If an overrun error is indicated the FIFO should be cleared using read(...).

Returns:

the error code (the values ar or-ed together):
1 -- Parity error
2 -- Framing error
8 -- UART overrun error
16 -- FIFO buffer overrun
Additionally there are some information flags (not cleared):
4 -- sndXOFF, remembers last sent XOFF state
32 -- recAbortLF, set if an readLine() is waiting for a linefeed character
64 -- recXOFF, remembers last received XOFF state
128 -- Inactive, set if the port is closed.

setCharacterGuardTime

public void setCharacterGuardTime(int bits)

Sets the character guard time, i.e. the time to wait between sending two characters over the serial port. Note that this value does not change the timeout, so on altering the character guard time, the application has to take care of adjusting the timeout appropriately (i.e. if guard time is set to 8, the timeout must be approximately doubled, as communication speed is cut down by 50%.

Parameters:

bits - minimum bits to wait between two characters

skip

public int skip(int n)
         throws IOException

skips n bytes of reading characters

Specified by:

skip in interface BasicInputStream

Parameters:

n - the number of bytes to skip

Returns:

the count of bytes that was skip'ed

Throws:

IOException - if an I/O error occurs.

flush

public void flush()
           throws IOException

flush unsent bytes (if exists)

Specified by:

flush in interface BasicOutputStream

Throws:

IOException - if an I/O error occurs.

mark

public void mark(int readlimit)

NOTE: not supported!

Specified by:

mark in interface BasicInputStream

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

markSupported

public boolean markSupported()

NOTE: not supported!

Specified by:

markSupported in interface BasicInputStream

Returns:

true if this stream instance supports the mark and reset methods; false otherwise.

reset

public void reset()
           throws IOException

NOTE: not supported!

Specified by:

reset in interface BasicInputStream

Throws:

IOException - if this stream has not been makred or if the mark has been invalidated.