Your systems. Working as one.

FACE Aligned Reference Platform:RTI TSS Reference Implementationbuilt on Connext DDS Cert

Dave Stringer, RTIApril 2016

Contents

• FACE TSS– Transport Services Segment Specification

• RTI TSS RI– RTI FACE 2.1 TSS Reference Implementation

• Connext DDS Cert– DO 178C Level A Product

TSS Context within FACE

• Data Model– Central to FACE Architecture– Captures Semantics– Shared Data Model for all Applications

• Configuration– Simple APIs assist in Portability– Complexity resides in Configuration Data

• Conformance– UoP – Unit of Portability– UoP author to provide a UoP Data Model– RTI TSS RI conforms to FACE Safety Base Profile

Transport Services API

• C++ API• 8 + 1 Functions

– FACE::TS::Initialize(…)– FACE::TS::Create_Connection(…)– FACE::TS::Receive_Message(…)– FACE::TS::Send_Message(…)– FACE::TS::Register_Callback(…)– FACE::TS::Unregister_Callback(…)– FACE::TS::Get_Connection_Parameters(…)– FACE::TS::Destroy_Connection(…)

– FACE::Read_Callback::send_event(…)

RTI TSS Reference Implementation

RTI TSS Type Plugin

Config Plugin

QoS Plugin

Configuration Mgr

ConfigEntryConfigEntry

Config Entry

Connection Mgr

ConfigEntryConfigEntryConnection

EntryLogger

Connext DDS Pro / Connext DDS Micro / Connext DDS Cert

FACE UoP FACE TS API

DDS Databus

DDS RTPS

Connext DDS Micro & Cert

• Data-centric Pub-Sub middleware– Loose coupling between data producers and data consumers

• Support resource constrained environments – Require as little as 41KB RAM, 350-500KB library size– Low CPU load (< 10%)

• Distributed as highly portable source code– Known to run on at least 11 operating systems– Supports bare metal with no OS

• Certified to DO-178C Level A– Evidence is available

• Common interaction semantics regardless of IPC mechanism– E.g., Shared memory, ARINC ports, UDP ockets

• Follow OMG DDS specification– RTPS wire protocol compatible– Peer-to-peer interoperability with other DDS implementations– Subset of standard DDS API

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Modular and Configurable Architecture

User Application

DDS API Subset

Transport API

Base-line configuration

OS API Queue API Discovery API

Listeners

Reliability

Durability & History

Other QoS

Optional APIs

Com

pile

-tim

e op

tions

Fully Dynamic DiscoveryUDPv4 Linux

Mobile Static Endpoint Discovery

Plug-in components

Linear Queue

Keyed QueueShared memory

RTOS

RTPS Windows

May 2, 2023 7

Connext DDS Inherently Well-Suited toSafety-Critical Systems• Non-stop availability– Decentralized architecture– No single point of failure– Support for redundant networks– Automatic failover between redundant publishers– Dynamic upgrades

• No central server or services• Version-independent interoperability protocol

• Control over real-time Quality of Service• Visibility into missed deadlines and presence• Proven in thousands of mission critical systems

8May 2, 2023

High-Assurance Safety: DO-178C/ED-12C

• Guideline• Used by FAA, EASA and

others to certifyairworthiness of civilaircraft• Also required for

integration of drones into civilian National Air Space• Generally acknowledged as most stringent safety

standardMay 2, 2023 9

DO-178C Level A Certification Evidence

• Plan for Software Aspects of Certification (PSAC)

• Software Development Plan (SDP)– Requirements standards– Design standards– Code standards

• Software Verification Plan (SVP)• Software Configuration

Management Plan (SCM)• Software Quality Assurance Plan

• Software Requirements Data• Design Description• Traceability• SQA Records• SCM Records• Software Configuration Index• Software Verification Cases and

Procedures• Software Verification Results• Software Accomplishment

Summary

Certification evidence can be re-used across programsMay 2, 2023 10

Connext DDS Cert Slashes Certification Costs

• Minimizes code for which certification evidence must be generated– Eliminates custom connectivity code– Rich capabilities reduce and simplify application logic

• Minimizes recertification effort as systems evolve– Encourages modularity– Decouples software modules and subsystems– Isolates changes

May 2, 2023 11

Summary

• RTI FACE 2.1 TSS RI– Reference Implementation– Builds on Connext DDS product family– FACE OS Safety Base Profile

• Connext DDS Cert designed for safety-critical applications– Code is certifiable to DO-178C/ED-12C Level A– Certification evidence is reusable

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