iNET Documentation

iNET is a FTI packet format that is decribed in IRIG106 standard, http://www.irig106.org/docs/106-17/Chapter24.pdf

It is typically encapsulated in a UDP payload. This module supports the creating and analysis of iNET packets

In typical use, a UDP payload is captured from the network or read from a PCAP file. This is then passed to the iNET.unpack() method which converts it into an iNET object

The payload of the iNET packet, is a list of iNETPackage objects

Examples and details are available below

iNET Objects

class AcraNetwork.iNET.iNET

Class to pack and unpack iNET payloads. iNET is standard packet format for use in FTI networks. It is usually transmitted in a UDP packet containing parameter data acquired from sensors and buses

The packet structure is defined in IRIG106 Chapter24 http://www.irig106.org/docs/106-17/Chapter24.pdf

Capture a UDP packet and unpack the _payload as an iNET packet

>>> from base64 import b64decode
>>> data = b64decode('EAAAAAAAAAYAAAAAAAAAGAAAAAAAAAAA')
>>> i = iNET()
>>> i.unpack(data)
True
>>> print(i.definition_ID)
6
pack() → bytes

Pack the packet into a binary format and return as a string

Return type:

str|bytes

unpack(buf: bytes) → bool

Unpack a raw byte stream to an iNET object Accepts a buffer to unpack as the required argument

Parameters:

buf (str) – The string buffer to unpack

Return type:

bool

app_fields

Optional Application Defined fields.

definition_ID

Message Definition ID

flags

Message Flags. Bits 15:8 Reserved.

packages: List[iNETPackage]

The payload is made up of packages. The packagaes are stored in this attribute list[iNETPackage]

ptptimenanoseconds

PTP timestamps in nanoseconds

ptptimeseconds

PTP timestamps in seconds

sequence

Message Sequence Number

type

Message type

version

Message version

iNETPackage Objects

class AcraNetwork.iNET.iNETPackage

The _payload of an iNET packet is multiple Package Headers. This class handles such objects

pack() → bytes

Pack the packet into a binary format and return as a string

unpack(buf: bytes) → bytes

Unpack a raw byte stream to an iNET package. Accepts a buffer to unpack as the required argument. Returns the unused buffer so that the unpack method can be called repeatedly

Parameters:

buf (str) – The string buffer to unpack

Return type:

str

definitionID: int

Package definition ID

flags: int

Package status Flags defined in the MDL document

payload: bytes

The package payload

timedelta: int

Package time relative to the parent Message timestamp in nanoseconds