Package org.yamcs.tctm

Class CcsdsPacket

java.lang.Object

org.yamcs.tctm.CcsdsPacket

public class CcsdsPacket
extends Object

CCSDS Packet as per CCSDS 133.0-B-2 https://public.ccsds.org/Pubs/133x0b2e1.pdf

 primary header (6 bytes):
  3 bit = version - 0
  1 bit = type (0 = TM, 1= TC)
  1 bit = 2nd header present
  11 bit = apid

  2 bit = grouping, 01 = first, 00 = cont, 10 = last packet of group, 11 = unsegmented data
  14 bit = seq

  16 bit = packet length (excluding primary header) minus 1
 

Field Summary

Fields

Modifier and Type	Field	Description
protected ByteBuffer	bb

Constructor Summary

Constructors

Constructor	Description
CcsdsPacket(byte[] packet)
CcsdsPacket(ByteBuffer bb)

Method Summary

Modifier and Type	Method	Description
protected void	appendBinaryData(StringBuilder sb)
int	getAPID()
static short	getAPID(byte[] packet)
static short	getAPID(ByteBuffer bb)
ByteBuffer	getByteBuffer()
byte[]	getBytes()
int	getCccsdsPacketLength()
static int	getCccsdsPacketLength(byte[] buf)
static int	getCccsdsPacketLength(ByteBuffer bb)
boolean	getChecksumIndicator()
static boolean	getChecksumIndicator(byte[] packet)
long	getCoarseTime()
int	getLength()	returns the length of the packet, normally equals ccsdslength+7
int	getSecondaryHeaderFlag()
static boolean	getSecondaryHeaderFlag(byte[] packet)
int	getSequenceCount()
static int	getSequenceCount(byte[] packet)
static short	getSequenceCount(ByteBuffer bb)
int	getTimeId()
void	setAPID(int apid)
void	setCccsdsPacketLength(short length)
void	setHeader(int apid, int tmtc, int secHeaderPresent, int seqFlags, int seq)	Write the header.
void	setSequenceCount(short seqCount)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

bb

protected ByteBuffer bb

Constructor Detail

CcsdsPacket

public CcsdsPacket(byte[] packet)

CcsdsPacket

public CcsdsPacket(ByteBuffer bb)

Method Detail

getSecondaryHeaderFlag

public int getSecondaryHeaderFlag()

getSecondaryHeaderFlag

public static boolean getSecondaryHeaderFlag(byte[] packet)

getSequenceCount

public int getSequenceCount()

getSequenceCount

public static int getSequenceCount(byte[] packet)

setSequenceCount

public void setSequenceCount(short seqCount)

getSequenceCount

public static short getSequenceCount(ByteBuffer bb)

getAPID

public int getAPID()

setHeader

public void setHeader(int apid,
                      int tmtc,
                      int secHeaderPresent,
                      int seqFlags,
                      int seq)

Write the header. The grouping is set to 10b = last packet in the group and the length to the capacity of the buffer (minus 7)

Parameters:

apid -

secHeaderPresent - 1 = present, 0 = absent

tmtc - 0 = tm, 1 = tc

seqFlags - grouping: 01 = first packet, 00 = continuation packet, 10 = last packet of group, 11 = unsegmented data

seq -

setAPID

public void setAPID(int apid)

getAPID

public static short getAPID(ByteBuffer bb)

getCccsdsPacketLength

public static int getCccsdsPacketLength(ByteBuffer bb)

getCccsdsPacketLength

public int getCccsdsPacketLength()

setCccsdsPacketLength

public void setCccsdsPacketLength(short length)

getLength

public int getLength()

returns the length of the packet, normally equals ccsdslength+7

getCoarseTime

public long getCoarseTime()

Returns:

time in seconds since 6 Jan 1980

getTimeId

public int getTimeId()

getChecksumIndicator

public boolean getChecksumIndicator()

getChecksumIndicator

public static boolean getChecksumIndicator(byte[] packet)

getBytes

public byte[] getBytes()

getByteBuffer

public ByteBuffer getByteBuffer()

getAPID

public static short getAPID(byte[] packet)

getCccsdsPacketLength

public static int getCccsdsPacketLength(byte[] buf)

toString

public String toString()

Overrides:

toString in class Object

appendBinaryData

protected void appendBinaryData(StringBuilder sb)