Current Developments in xDS Device
Descriptions
Matthew Frazer (ODVA)
Todd Andrew Snide (Schneider Electric)

Internal

Introduction
The xDS SIG is developing the next generation digital device
description. This presentation highlights the current design
considerations:• Use of AutomationML as a basis for modeling device information.
• Security considerations• Use of Open Packaging Conventions as a means of packaging theinformation.
• Proposed xDS toolingTechnical Track© 2022 ODVA, Inc.

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2

What is xDS?
•••

The goal: A simple, scalable, secure, reusable digital device description.
Includes all necessary information to configure, monitor, control, diagnose,and test CIP devices.
Supporting workflows:–––––

Network and Security Configuration
Device Configuration
Network Diagnostics
Device Diagnostics
Device Conformance

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2022 Industry Conference & 21st Annual Meeting
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3

AutomationML
••
•
•
•

AML was developed for automation dataexchange interconnecting engineering
tools.
Established Organization with support.
AML tools exist: editor, engine, libraries.
Library, tutorial and usage documentation
available.
Other consortia have adopted AML:
– Asset Administration Shell for Industrie 4.0– Others– Potentially allows sharing descriptors
across other systems

Technical Track© 2022 ODVA, Inc.

2022 Industry Conference & 21st Annual Meeting
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4Modeling CIP Devices using AML• In depth details on AML are out of scope in the presentation• Basic AML concepts needed for xDS Device Description:– RoleClass: Abstract semantic information about an object– SystemUnitClass: Reusable format representing a specific object type• Contains at least one RoleClass– InterfaceClass: Models an interface between components• All can be collected into class libraries– Custom libraries can be created• An ODVA xDS Primitives Library will be createdTechnical Track© 2022 ODVA, Inc.

2022 Industry Conference & 21st Annual Meeting
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5xDS Hierarchy
CAEXAutomationML••••

AML Base Libraries
xDS Primitives Libraries

Created and supplied by ODVA.
Based on the xDS specification.

Role Class Lib
Interface Class Lib
Attribute Type Lib

CIP Device Description Model

Predefined form for modeling a CIP Device in a System Unit Class Lib

Specific xDS Device Model
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2022 Industry Conference & 21st Annual Meeting
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The xDS specification will define
the format.
Generated by the vendor.

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6

Use of ODVA xDS Primitives•

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The ODVA-provided
xDS Primitives Library
can be used by toolsthat create or interpret
an xDS artifact

www.odva.org

7xDS CIP Device Description Model•

CIP Device modeled according toAML communications model– The physical device describes
identification information– The logical device provides
constructs to describe logicalinterfaces••••

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2022 Industry Conference & 21st Annual Meeting
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Parameters
Assemblies
I/O Connections
Featureswww.odva.org

8xDS Primitives – RoleClass Library
Device – A physical CIP device.
••

EtherNet/IPDevice – EtherNet/IP implementation
DeviceNetDevice – DeviceNet implementation

CIPDeviceDescription – CIP logical device model.
•••••

ConnectionList – Container for I/O connections
ParameterGroup – Container for parameters
AssemblyList – Container for CIP assemblies
FeatureList – Container for specific feature definitions
CIPObjectModel – Object model container

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9xDS Primitives – InterfaceClasses• Parameter – Model of a single configuration parameter– Could represent a CIP Parameter but is not required to do so• Connection – Model of a single supported I/O connection• Assembly – Model of a CIP Assembly, to include the assembly
layoutTechnical Track© 2022 ODVA, Inc.

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10

A CIP Device Model Example
Vendor ID
Device Type
Product CodeRevision
Product Name

24 – ODVA
7 – General Purpose Discrete IO Device
201.001
Virtual Discrete IO Device

ObjectIdentity
Message Router
Ethernet Link
TCP/IP Interface
Connection Manager
Assembly
Discrete Input Point
Discrete Output
Point

Reference Device Identity

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Reference Device
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Instances111
1
13, 33, 100
1, 2, 3, 4
1, 2, 3, 4

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xDS Representation of a CIP Device
Library container of devices
Physical device description
Logical device description

Parameter Groups

Assembly Groups
I/O Connection Definitions
CIP Object Model Description(not yet defined)
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CIP Device Attributes

Identity Attributes
Assembly Attributes
Connection Attributes
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Security Considerations - Threat Model
Threat Model Primary Use Cases• Vendor Device Deployment

Primary Areas of Concern• Invalid xDS device descriptions– Vendor will digitally sign xDS artifact.

– Accidental or maliciousmodifications.

••

Nonconformant device

ODVA Conformance– Upon successful testing ODVA will:– Misrepresenting a device asconformant.

• Insert a DoC.
• Digitally sign the DoC & parts of xDS•

End User Tools– End User tools will validate an xDS
artifact upon uploading

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xDS Packaging - Open Packaging Conventions••••

ISO 29500-2 & ECMA-376.
Structured storage in a “zip” file.
Expression of relationships between parts through a directed graph ofassociations.
Multiple, independent digital signatures based on portions of the content.

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xDS Packaging – Proposed Sections
SectionPart of Vendor
Signature

Version Information

Required

AML Device Descriptions

RequiredGraphics

Optional

Icons

Optional

Localization String Tables

Optional

Legacy EDS Files

Optional

Vendor Documentation

Optional

Vendor Specific Files

Optional

Part of ODVA
Signature
Required

ODVA Conformance

Required

Signatures
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xDS Tools•“EZ-xDS”

DeviceNativeDeviceDeviceData

CIP
Discovery
Tool

Operator
Supplied
Data

ManualInputs &Overrides

LegacyEDS/STC
Data Files•

Data
ValidationxDS Data
Serializer

SerializedxDS Data

EDS-xDS
ConverterxDS Reference Implementation– Opensource reference to demonstrate how to read and interpret xDS information

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17Internal