Module org.yamcs.core

Package org.yamcs.tctm.cfs

Class CfsPacketPreprocessor

java.lang.Object

org.yamcs.tctm.AbstractPacketPreprocessor

org.yamcs.tctm.CcsdsPacketPreprocessor

org.yamcs.tctm.cfs.CfsPacketPreprocessor

All Implemented Interfaces:

PacketPreprocessor

public class CfsPacketPreprocessor
extends CcsdsPacketPreprocessor

Preprocessor for the CFS TM packets:

• CCSDS primary header 6 bytes
• Time seconds 4 bytes
• subseconds(1/2^16 fraction of seconds) 2 bytes

Options:

   dataLinks:
   ...
      packetPreprocessor: org.yamcs.tctm.cfs.CfsPacketPreprocessor
      packetPreprocessorArgs:
          byteOrder: LITTLE_ENDIAN
          timeEncoding:
              epoch: CUSTOM
              epochUTC: 1970-01-01T00:00:00Z
              timeIncludesLeapSeconds: false
 
 

The byteOrder option (default is BIG_ENDIAN) is used only for decoding the timestamp in the secondary header: the 4 bytes second and 2 bytes subseconds are decoded in little endian.

The primary CCSDS header is always decoded as BIG_ENDIAN.

For explanation on the timeEncoding property, please see AbstractPacketPreprocessor. The default timeEncoding used if none is specified, is GPS, equivalent with this configuration:

 timeEncoding:
     epoch: GPS
 

which is also equivalent with this more detailed configuration:

 timeEncoding:
     epoch: CUSTOM
     epochUTC: "1980-01-06T00:00:00Z"
     timeIncludesLeapSeconds: true
 

Nested Class Summary

Nested classes/interfaces inherited from class org.yamcs.tctm.AbstractPacketPreprocessor

AbstractPacketPreprocessor.TimeDecoderType, AbstractPacketPreprocessor.TimeEpochs

Field Summary

Fields inherited from class org.yamcs.tctm.AbstractPacketPreprocessor

byteOrder, checkForSequenceDiscontinuity, CONFIG_KEY_BYTE_ORDER, CONFIG_KEY_CHECK_SEQUENCE, CONFIG_KEY_ERROR_DETECTION, CONFIG_KEY_TCO_SERVICE, CONFIG_KEY_TIME_ENCODING, customEpoch, customEpochIncludeLeapSecond, errorDetectionCalculator, eventProducer, log, tcoService, timeDecoder, timeEpoch, timeService, useLocalGenerationTime

Constructor Summary

Constructors

Constructor	Description
CfsPacketPreprocessor(String yamcsInstance)
CfsPacketPreprocessor(String yamcsInstance, YConfiguration config)

Method Summary

Modifier and Type	Method	Description
TmPacket	process(TmPacket pkt)	Processes the packet and returns it.

Methods inherited from class org.yamcs.tctm.CcsdsPacketPreprocessor

checkSequence

Methods inherited from class org.yamcs.tctm.AbstractPacketPreprocessor

checkForSequenceDiscontinuity, checkForSequenceDiscontinuity, getByteOrder, getDefaultDecoderType, getErrorDetectionWordCalculator, setRealtimePacketTime, shiftFromEpoch, verifyCrc

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.yamcs.tctm.PacketPreprocessor

process

Constructor Details

CfsPacketPreprocessor

public CfsPacketPreprocessor(String yamcsInstance)

CfsPacketPreprocessor

public CfsPacketPreprocessor(String yamcsInstance,
 YConfiguration config)

Method Details

process

public TmPacket process(TmPacket pkt)

Description copied from interface: PacketPreprocessor

Processes the packet and returns it.

What this function does is project depended. However, we expect that the generation time and sequence count are filled in.

Can return null if the packet is to be ignored.

Parameters:

pkt - - the packet that has to be processed

Returns:

the processed packet