PusPacketPreprocessor (Yamcs :: Core 5.3.2 API)

java.lang.Object
- org.yamcs.tctm.AbstractPacketPreprocessor
- - org.yamcs.tctm.pus.PusPacketPreprocessor

All Implemented Interfaces:

PacketPreprocessor
```
public class PusPacketPreprocessor
extends AbstractPacketPreprocessor
```
Implementation for ECSS PUS (ECSS-E-ST-70-41C) packets. The header structure is:
Primary header (specified by CCSDS 133.0-B-1)
- packet version number (3 bits)
- packet type (1 bit)
- secondary header flag (1 bit)
- application process ID (11 bits)
- sequence flags (2 bits)
- packet sequence count (14 bits)
Secondary header (PUS specific)
- TM packet PUS version number (4 bits)
- spacecraft time reference status (4 bits)
- service type ID (8 bits)
- message subtype ID (8 bits)
- message type counter (16 bits)
- destination ID (16 bits)
- time (absolute time) variable
- spare optional
The time packets have no secondary header and the apid set to 0. The data part consists of the current onboard time in the same encoding like in the normal packets.
In this class we are interested in the time and the sequence count.

- Nested Class Summary
  - Nested classes/interfaces inherited from class org.yamcs.tctm.AbstractPacketPreprocessor
    AbstractPacketPreprocessor.TimeEpochs
- Field Summary
  - Fields inherited from class org.yamcs.tctm.AbstractPacketPreprocessor
    byteOrder, 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
  
  PusPacketPreprocessor(String yamcsInstance)
  
  PusPacketPreprocessor(String yamcsInstance, YConfiguration config)
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  TmPacket process(TmPacket tmPacket)
  Processes the packet and returns it.
  - Methods inherited from class org.yamcs.tctm.AbstractPacketPreprocessor
    getErrorDetectionWordCalculator, shiftFromEpoch
  - 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
    checkForSequenceDiscontinuity, process

- Constructor Detail
  - PusPacketPreprocessor
```
public PusPacketPreprocessor(String yamcsInstance)
```
  - PusPacketPreprocessor
```
public PusPacketPreprocessor(String yamcsInstance,
                             YConfiguration config)
```
- Method Detail
  - process
```
public TmPacket process(TmPacket tmPacket)
```
    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:
    
    tmPacket - - the packet that has to be processed
    
    Returns:
    
    the processed packet