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Ensuring Reliable Networks

Copyright © TTTech Computertechnik AG. All rights reserved.

Distributed IMA with

TTEthernetARINC 653 Integration of TTEthernet

Georg Gaderer, Product Manager

[email protected]

October 30, 2012

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Introduction

What is the enabler for (D)IMA?

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Introduction

Where is it going?

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COTS Ethernet

Free-Form Communication

No performance guarantees:

Best-efforts

Low cost

Standards:

Ethernet, TCP/IP, UDP, FTP,

Telnet, SSH, ...

Applications:

Multi-media, audio, video, phones,

PDAs, internet, web, …

Validation & verification:

No certification, test, simulation, ...

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Airborne Networks

Statically Configured Communication

Performance guarantees:

real-time, dependability, safety

High cost

Standards:

ARINC 664, ARINC 429, TTP,

MOST, FlexRay, CAN, LIN, …

Applications:

Flight control, powertrain, chassis,

passive and active safety, ..


Certification, formal analysis, ...




High cost

Standards:



Applications:





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Communication Types

We see a market requirement to use the same physical network

for data flows from both worlds.

?

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Communication Types




High cost

Standards:



Applications:





Free-Form Communication

No performance guarantees:

Best-efforts

Low cost

Standards:

Ethernet, TCP/IP, UDP, FTP,

Telnet, SSH, ...

Applications:

Multi-media, audio, video, phones,

PDAs, internet, web, …


No certification, test, simulation, ...

We see a market requirement to use the same physical network

for data flows from both worlds.




High cost

Standards:



Applications:





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Cross-Industrial Perspectives

Aerospace Automotive Off-Highway

FT-COM

OSEKtime

COM

OSEK

LIN / TTP/A

Master

Driver

Driver

Driver

Gateway & Routing / Event Layer / ISO 15765-2 / HAL

TTPOS

Time-Triggered

OSEKtime

ET-OS

OSEK

Boot-

loader

Flasher

Net Mgmt.

OSEK

Diagnostic Prot.

e.g. ISO 14229-1

Calibration

Data Display

Industrial

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Mixed-Criticality Systems- A Maze

Interne

t

Safety-, Time- or Mission Critical

Standard LAN

Open Networks

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TTEthernet Traffic Types

TTEthernet

TT

Base Period

t

Base Period

RC TT ET TT ET TT ET TT ET TT TT RC ETET RC

P base P base P base P base2 x P base 2 x P base4 x P base

Longest Communication Period in this Example: 4 x Base Period

Base Period Base Period

TT TTRC

Sy

nc

hro

no

us

(TD

M)

Tra

ffic

TTEthernet

Enables:

delivery of synchronous services,

A/V, critical controls,

low-latency and standard LAN apps

in one network

Ra

te-

Co

ns

tra

ine

d

Lo

ss

les

sIE

EE

AV

B/D

CB

Be

st-

Eff

ort

(B

E)

Eth

ern

et

Tra

ffic

Pri

ori

ty-b

as

ed

As

yn

ch

ron

ou

s

Eth

ern

et

Tra

ffic

TTEthernet

Enables delivery of synchronous

services, low latencies, one one

LAN

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TTEthernet For Mixed Criticality

TTEthernet = combination on the same network of

SAE AS6802

• synchronous

• jitter < 1 ms

• latency < 12.5

ms/switch (1 GBit/s

Ethernet)

• very tight control

loops

ARINC664p7

• asynchronous

• jitter < 500 ms

• latency typical 1-10

ms

• TTTech AFDX

licensee

IEEE802.3

• best effort Ethernet

• no performance

guarantee

+ certifiable according to RTCA DO-254 DAL A and IEC 61508 (SIL)

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Fault-Tolerant Synchronized

Global Time

TTE

1588

1588

Eth

TTE

TTE

TTE

Eth

TTE

TTE

TTE

TTE

TTE

TTE

TTE

Eth

Fault-tolerant global time base established by

SAE AS 6802 protocol services as basis for

time-triggered communication!

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RECEIVERSENDER

MIDDLEWARE

NETWORK

MIDDLEWARE

NETWORK

SYNC LEVEL 1

(NETWORK)

syn

c

SYNC LEVEL 2

(MIDDLEWARE)

syn

c

SYNC LEVEL 3

(APP. LEVEL)

syn

c

Interface to physical

systems synchronized

(simpified sensor fusion)

Redundancy Mgmt

(Voting)

Comm. Abstraction

Network – Temporal

behavior for all critical

functions defined here!!!

Layering Aspects

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TTEthernet and IMA

• Integrated Modular Avionics (IMA)• New functionality often causes major system redesign

• New functional requirements• Higher communication bandwidth

• Increased criticality

• Scalability (for different platforms)

• Flexibility (for adding new functions)

• Distributed IMA (DIMA)• Distribute IMA applications across the network

• However, DIMA Implies/Requires• Mixed-criticality of software and communication subsystems

• Robust partitioning in software and communication systems

• Higher needed communication bandwidth

• More “determinism” on the data bus is crucial (higher utilization)

• Idea: Bringing together TTTech’s scalable TTEthernet communication platform with the power of time and space partitioning IMA operating systems

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Key Features

TTEthernet enabled ARINC 653

• Application level

• Communication

system level

IMA OS

ModuleP1 P2 P3 P4 P1 P2 P3 P4

tMajor time frame, e.g., 20ms

tCluster cycle, e.g., 20ms

TT TT TTRC

ET RC TT TT

RC

TT

TT ETTx

Rx

TT TT TTRC

ET RC TT TT

RC

TT

TT ET

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Key Benefits

• High re-use of already well-established solutions• Can be integrated in operating systems on the market (e.g., ARINC 653)

• Re-use of existing communication mechanisms (e.g., sampled/queued ports in ARINC 653) as interface for message exchange

• Brings the benefits of TTEthernet into IMA architectures• High-speed communication (up to 1Gbit/s), scalable speed grades

10/100/1000Mbit/s

• Scalable fault-tolerance (no, single, or double fault-tolerance)

• Chip IP certification package according to DO254

• Enables the benefits of time-triggered technology in IMA architectures• Efficient implementation of fault-tolerance by replicated functionality (supported by highly-

deterministic data bus)

• Testability; beneficial for improvement of design and integration processes

• Emerging advantages• Using the highly precise (sub microsecond) fault-tolerant time base of TTEthernet for

synchronizing modules / partitions

• This allows setting up “standard” partition applications and additionally enabling “time-triggered” operation of partitions

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TTECOM Layer ARINC 653

• TTEthernet middleware (ARINC 653)

• Queuing and sampling ports

• DMA support

• Library for invocation of IMA partitions (Synchronization)

Task 1A Task 1B

Partition 1 Partition 2

Core OS IMA OS Message

Channel API

Hardware

TT RC BE

Message Channels (sampled and queued ports)

TTEPCI Driver

TTEAPI Library

TTECOM Layer ARINC 653

Task 2A Task 2B

Partition OSPartition OS

Task 3A

Partition OS

Partition 3

Core OS Services

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TTEthernet DIMA Demonstrator

TTEthernet Network

0 1

Module 2

Module 1 P1,1

P2,1

[ms]

[ms] # Frames kBytes Mbit/s

1 20 1,5 251,28

Module 1

PPC hardware board +

TTTech TTEPMC Card

Module 2

PPC hardware board +

TTTech TTEPMC Card

Switch 1 Switch 2

Oscilloscope

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Lab Setup – DIMA Demo

Module 1

Module 2

Module

1

S P1,1 P1,2

t

Module

2

S P1,1 P1,2

S P2,1 P2,2S P2,1 P2,2

Major time frame = 20ms

Video 1: Tx partition

Video 2: Drift + resync

C:/Documents and Settings/products/ttethernet-products/_presentations/_drafts/video/tx_part.avi

C:/Documents and Settings/products/ttethernet-products/_presentations/_drafts/video/drift.avi

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Key Characteristics

• Input/Output of Messages• Pseudo-port driver

• Direct-access port driver

• Synchronization

• TTEthernet clock synchronization <1 µs

• Partition synchronization ~ 1.5µs precision

• Communication• Multi-hop setup

• 2 end systems

• 2 switches

• message latency • ~20µs per switch hop,

• 15µs per E/S (

• 50µs end-to-end latency of the network Bandwidth possible up to 250 Mbit/s, depending on host platform and application architecture

• Fault-Tolerance

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Conclusion

• Distributed IMA Demonstrator based on • ARINC 653 time and space partitioned real-time operating system

• TTEthernet scalable safety-critical real-time high-speed deterministic Ethernet communication technology

• Bringing• Low-latency,

• minimal jitter,

• and high-bandwidth communication (80%!) up to the application level

• Enabling• Distributed IMA applications,

• robust

• fault-tolerant sync support,

• increase of • determinism

• testability

• convenient development and integration processes