jmri.jmrix.can.adapters.gridconnect.canrs
Class MergMessage

java.lang.Object
  jmri.jmrix.AbstractMessage
      jmri.jmrix.AbstractMRMessage
          jmri.jmrix.can.adapters.gridconnect.GridConnectMessage
              jmri.jmrix.can.adapters.gridconnect.canrs.MergMessage

All Implemented Interfaces:

Message

public class MergMessage
extends GridConnectMessage

Class for messages for a MERG CAN-RS hardware adapter.

The MERG varient of the GridConnect protocol encodes messages as an ASCII string of up to 24 characters of the form: :ShhhhNd0d1d2d3d4d5d6d7; hhhh is the two byte (11 useful bits) header The S indicates a standard CAN frame :XhhhhhhhhNd0d1d2d3d4d5d6d7; The X indicates an extended CAN frame Strict Gridconnect protocol allows a variable number of header characters, e.g., a header value of 0x123 could be encoded as S123 rather than S0123 or X00000123. We choose a fixed number, either 4 or 8 bytes when sending GridConnectMessages to keep MERG CAN-RS/USB adapters happy. The 11 bit standard header is left justified in these 4 bytes. The 29 bit standard header is sent as <11 bit SID><0><1><0>< 18 bit EID> N or R indicates a normal or remote frame, in position 6 or 10 d0 - d7 are the (up to) 8 data bytes

Author:

Andrew Crosland Copyright (C) 2008

Field Summary

Fields inherited from class jmri.jmrix.AbstractMRMessage

LONG_TIMEOUT, SHORT_TIMEOUT

Fields inherited from class jmri.jmrix.AbstractMessage

_dataChars, _nDataChars

Constructor Summary

MergMessage()

MergMessage(CanMessage m)

Method Summary

void	setByte(int val, int n) Set a byte as two ASCII hex digits Data bytes are encoded as two ASCII hex digits starting at byte 7 of the message.
void	setHeader(int header) Set the header in MERG format
void	setRtr(boolean rtr)

Methods inherited from class jmri.jmrix.can.adapters.gridconnect.GridConnectMessage

getElement, getNumDataElements, isExtended, setData, setElement, setExtended, setHexDigit, setNumDataElements

Methods inherited from class jmri.jmrix.AbstractMRMessage

addIntAsFourHex, addIntAsThree, addIntAsThreeHex, addIntAsTwoHex, getNeededMode, getOpCode, getOpCodeHex, getRetries, getTimeout, isBinary, replyExpected, setBinary, setNeededMode, setOpCode, setRetries, setTimeout, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

MergMessage

public MergMessage()

MergMessage

public MergMessage(CanMessage m)

Method Detail

setHeader

public void setHeader(int header)

Set the header in MERG format

Overrides:

setHeader in class GridConnectMessage

Parameters:

header - A valid CAN header value

setRtr

public void setRtr(boolean rtr)

Overrides:

setRtr in class GridConnectMessage

setByte

public void setByte(int val,
                    int n)

Set a byte as two ASCII hex digits

Data bytes are encoded as two ASCII hex digits starting at byte 7 of the message.

Overrides:

setByte in class GridConnectMessage

Parameters:

val - the value to set

n - the index of the byte to be set