net.wimpi.modbus.util
Class ModbusUtil

java.lang.Object
  net.wimpi.modbus.util.ModbusUtil

public final class ModbusUtil
extends Object

Helper class that provides utility methods.

Version:

@version@ (@date@)

Author:

Dieter Wimberger, John Charlton

Constructor Summary

ModbusUtil()

Method Summary

static int[]	calculateCRC(byte[] data, int offset, int len)
static int	calculateLRC(byte[] data, int off, int len)
static byte[]	doubleToRegisters(double d) Converts a double value to a byte[8].
static byte[]	floatToRegisters(float f) Converts a float value to a byte[4] binary float value.
static byte	hiByte(int wd)
static byte[]	intToRegisters(int v) Converts an int value to a byte[4] array.
static byte[]	longToRegisters(long v) Converts a long value to a byte[8].
static byte	lowByte(int wd) Returs the low byte of an integer word.
static int	makeWord(int hibyte, int lowbyte)
static double	registersToDouble(byte[] bytes) Converts a byte[8] binary double value into a double primitive.
static float	registersToFloat(byte[] bytes) Converts a byte[4] binary float value to a float primitive.
static int	registersToInt(byte[] bytes) Converts a byte[4] binary int value to a primitive int. The value returned is:
static long	registersToLong(byte[] bytes) Converts a byte[8] binary long value into a long primitive.
static short	registerToShort(byte[] bytes) Converts the given register (16-bit value) into a short.
static short	registerToShort(byte[] bytes, int idx) Converts the register (16-bit value) at the given index into a short.
static int	registerToUnsignedShort(byte[] bytes) Converts the register (a 16 bit value) into an unsigned short.
static byte[]	shortToRegister(short s) Converts the given short into a register (2 bytes).
static String	toHex(byte[] data) Returns the given byte[] as hex encoded string.
static String	toHex(byte[] data, int off, int length) Returns a String containing unsigned hexadecimal numbers as digits.
static byte[]	toHex(int i) Returns a byte[] containing the given byte as unsigned hexadecimal number digits.
static String	toHex(ModbusMessage msg) Converts a ModbusMessage instance into a hex encoded string representation.
static int	unsignedByteToInt(byte b) Converts an unsigned byte to an integer.
static byte[]	unsignedShortToRegister(int v) Converts the given unsigned short into a register (2 bytes).

Methods inherited from class java.lang.Object

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

Constructor Detail

ModbusUtil

public ModbusUtil()

Method Detail

toHex

public static final String toHex(ModbusMessage msg)

Converts a ModbusMessage instance into a hex encoded string representation.

Parameters:

msg - the message to be converted.

Returns:

the converted hex encoded string representation of the message.

toHex

public static final String toHex(byte[] data)

Returns the given byte[] as hex encoded string.

Parameters:

data - a byte[] array.

Returns:

a hex encoded String.

toHex

public static final String toHex(byte[] data,
                                 int off,
                                 int length)

Returns a String containing unsigned hexadecimal numbers as digits. The String will coontain two hex digit characters for each byte from the passed in byte[].
The bytes will be separated by a space character.

Parameters:

data - the array of bytes to be converted into a hex-string.

off - the offset to start converting from.

length - the number of bytes to be converted.

Returns:

the generated hexadecimal representation as String.

toHex

public static final byte[] toHex(int i)

Returns a byte[] containing the given byte as unsigned hexadecimal number digits.

Parameters:

i - the int to be converted into a hex string.

Returns:

the generated hexadecimal representation as byte[].

registerToUnsignedShort

public static final int registerToUnsignedShort(byte[] bytes)

Converts the register (a 16 bit value) into an unsigned short. The value returned is:

(((a & 0xff) << 8) | (b & 0xff))
 

This conversion has been taken from the documentation of the DataInput interface.

Parameters:

bytes - a register as byte[2].

Returns:

the unsigned short value as int.

See Also:

DataInput

unsignedShortToRegister

public static final byte[] unsignedShortToRegister(int v)

Converts the given unsigned short into a register (2 bytes). The byte values in the register, in the order shown, are:

 (byte)(0xff & (v >> 8))
 (byte)(0xff & v)
 

This conversion has been taken from the documentation of the DataOutput interface.

Parameters:

v -

Returns:

the register as byte[2].

See Also:

DataOutput

registerToShort

public static final short registerToShort(byte[] bytes)

Converts the given register (16-bit value) into a short. The value returned is:

 (short)((a << 8) | (b & 0xff))
 

This conversion has been taken from the documentation of the DataInput interface.

Parameters:

bytes - bytes a register as byte[2].

Returns:

the signed short as short.

registerToShort

public static final short registerToShort(byte[] bytes,
                                          int idx)

Converts the register (16-bit value) at the given index into a short. The value returned is:

 (short)((a << 8) | (b & 0xff))
 

This conversion has been taken from the documentation of the DataInput interface.

Parameters:

bytes - a byte[] containing a short value.

idx - an offset into the given byte[].

Returns:

the signed short as short.

shortToRegister

public static final byte[] shortToRegister(short s)

Converts the given short into a register (2 bytes). The byte values in the register, in the order shown, are:

 (byte)(0xff & (v >> 8))
 (byte)(0xff & v)
 

Parameters:

s -

Returns:

a register containing the given short value.

registersToInt

public static final int registersToInt(byte[] bytes)

Converts a byte[4] binary int value to a primitive int.
The value returned is:

 
 (((a & 0xff) << 24) | ((b & 0xff) << 16) |
  ((c & 0xff) << 8) | (d & 0xff))
 

Parameters:

bytes - registers as byte[4].

Returns:

the integer contained in the given register bytes.

intToRegisters

public static final byte[] intToRegisters(int v)

Converts an int value to a byte[4] array.

Parameters:

v - the value to be converted.

Returns:

a byte[4] containing the value.

registersToLong

public static final long registersToLong(byte[] bytes)

Converts a byte[8] binary long value into a long primitive.

Parameters:

bytes - a byte[8] containing a long value.

Returns:

a long value.

longToRegisters

public static final byte[] longToRegisters(long v)

Converts a long value to a byte[8].

Parameters:

v - the value to be converted.

Returns:

a byte[8] containing the long value.

registersToFloat

public static final float registersToFloat(byte[] bytes)

Converts a byte[4] binary float value to a float primitive.

Parameters:

bytes - the byte[4] containing the float value.

Returns:

a float value.

floatToRegisters

public static final byte[] floatToRegisters(float f)

Converts a float value to a byte[4] binary float value.

Parameters:

f - the float to be converted.

Returns:

a byte[4] containing the float value.

registersToDouble

public static final double registersToDouble(byte[] bytes)

Converts a byte[8] binary double value into a double primitive.

Parameters:

bytes - a byte[8] to be converted.

Returns:

a double value.

doubleToRegisters

public static final byte[] doubleToRegisters(double d)

Converts a double value to a byte[8].

Parameters:

d - the double to be converted.

Returns:

a byte[8].

unsignedByteToInt

public static final int unsignedByteToInt(byte b)

Converts an unsigned byte to an integer.

Parameters:

b - the byte to be converted.

Returns:

an integer containing the unsigned byte value.

lowByte

public static final byte lowByte(int wd)

Returs the low byte of an integer word.

Parameters:

wd -

Returns:

the low byte.

hiByte

public static final byte hiByte(int wd)

Parameters:

wd -

Returns:

the hi byte.

makeWord

public static final int makeWord(int hibyte,
                                 int lowbyte)

Parameters:

hibyte -

lowbyte -

Returns:

a word.

calculateCRC

public static final int[] calculateCRC(byte[] data,
                                       int offset,
                                       int len)

calculateLRC

public static final int calculateLRC(byte[] data,
                                     int off,
                                     int len)