org.avineas.modbus

Class ModbusPacket

java.lang.Object

org.avineas.modbus.ModbusPacket

Direct Known Subclasses:

ModbusRequest, ModbusResponse

public class ModbusPacket
extends java.lang.Object

Modbus packet as sent at application level. This class is the base for all other packets at application level and consists of a function code and the contents of the packet. Next to that, the class contains static methods for encoding and decoding words to bytes and v.v.

Method Summary

Methods

Modifier and Type	Method and Description
static int[]	decode(byte[] data, int offset, int length) Decode a part of contents as integer/word array.
static byte[]	encode(int[] data) Encode a number of words, encoded as integer values to bytes.
int	getFunction() Get the function code of this packet.
byte[]	toBytes() Convert this packet to bytes.

Methods inherited from class java.lang.Object

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

Method Detail

getFunction

public int getFunction()

Get the function code of this packet.

Returns:

The function code, as integer

toBytes

public byte[] toBytes()

Convert this packet to bytes. This is the normal method used before sending the packet over a link.

Returns:

The packet as a byte array

encode

public static byte[] encode(int[] data)

Encode a number of words, encoded as integer values to bytes. The encoding is done according to the Modbus specification, meaning high byte first.

Parameters:

data - The data to encode

Returns:

The byte array with the encoded data as present in a packet

decode

public static int[] decode(byte[] data,
           int offset,
           int length)

Decode a part of contents as integer/word array.

Parameters:

data - The data to decode from

offset - The starting offset to start decoding

length - The lengh to decode, in bytes

Returns:

An integer array giving the values of the words in the decoded stream