Extending EtherNet/IPTM to ResourceConstrained Industrial Things

Dayin XU, Rockwell Automation
Paul Brooks, Rockwell Automation
October 14, 2015

Agenda•••••••••

IoT Opportunities for ODVAConstrains of IoT and IIoT Things
Approaches to Connect IoT and IIoT Things to EtherNet/IP System
Barriers in EtherNet/IP Hardware Interface
Barriers in EtherNet/IP Protocol Firmware
Single Pair Ethernet as a New PHY Layer
UDP-capable Unconnected Explicit Message
Scalable EtherNet/IP StackConclusion

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IoT and IIoT Things•

Potential Industrial IoT Things– Industrial Sensors– Industrial Actuators– Process Instruments•

IoT Things––––Temperature sensor
Humidity sensor
Smoke detector
Light control

Ref: http://www.ipso-alliance.org/
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IoT Opportunities for ODVA•Grow ODVA ecosystem– Connect IoT things– Engage IoT vendors– Adopt IoT technologies

IoT
Industrial IoTAutomation

Can I addvalue?
ThingsProcessOptimization
ODVA

Vendors

Downtime
avoidance

CIP andEtherNet/IP

I need tointegrate
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Technologies

RemoteExpert

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IoT Opportunities for Members•Increase Device Connectivity–––––

Reduce integration cost
Increase connection flexibility
IoT Technologies
Wider cable reach
Cloud services
Microprocessors
Adopt IoT technologies

Can I add
value?

Downtime
avoidance

Software/CoAP

CIP and
EtherNet/IP

I need toexpand

RemoteExpert

Cloud & Big
Data2015 Industry Conference & 17th Annual Meeting
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Automation
Process
Optimization

Cables &Connectors

ODVA

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Industrial IoT

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5Constraints of IoT and IIoT Things•

Hardware Constraints– Cost ($1-2 incremental cost)– Size (<10cm2, 5cm2 may be typical)– Power consumption (<2W, 1W may be typical – even lower in Ex areas)•Resource Constraints––––

Computation power (Cortex-M3 100Mhz)
Memory (128Kbytes Flash, 32-64Kbytes RAM)
Energy (battery-powered)Communication bandwidth (lower data rate 500Kbps)

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6Evolution of IoT Hardware and Firmware
Value
Integration
Expansion

Reduction

EvolutionIntegration

Innovation

Ref: https://datatracker.ietf.org/wg/6lo/charter/
Ref: https://datatracker.ietf.org/wg/core/charter/
Ref: https://datatracker.ietf.org/wg/6lowpan/documents/

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IIoT/CIP Device Integration Future StateCIPDevice

IoTDevice

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$$$ODVA
System$$$Open IoT
System2015 Industry Conference & 17th Annual Meeting
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Proxy Approach
CIPDevice

Gateway
CIP
DeviceODVA
SystemTechnical Track© 2015 ODVA, Inc.

Open IoT
SystemIoT
DeviceGateway
IoT
Device2015 Industry Conference & 17th Annual Meeting
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9Proxy Approach Challenges for IoT Vendors•••

Lack of competence to develop gateway
Lack of knowledge to program/configure gateway
Loss of end-to-end connectivity

ODVA
SystemTechnical Track© 2015 ODVA, Inc.

IoT
DeviceGateway
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10Direct Connect Approach

ODVA
SystemCIP Device
implementing IoT
protocolCIP Device
implementing IoT
protocolTechnical Track© 2015 ODVA, Inc.

IoT Device
implementing
CIP

Ethernet
Switch / IP
RouterIoT Device
implementing
CIP

Ethernet
Switch / IP
Router2015 Industry Conference & 17th Annual Meeting
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Open IoT
Systemwww.odva.org

11Can IoT Platform be addressed by CIP Device?
•Out of scopeTechnical Track© 2015 ODVA, Inc.

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12Can EtherNet/IP be Implemented on IoT Platform?
••••

Multiple types of physical layers
IPv4 and IPv6
UDP-only capable, TCP optional
Resource constraints– Limited computation, memory, bandwidth and energy•

Hardware constraints– Limited cost, size and power consumption

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Cost and Size Barriers in EtherNet/IP Hardware•

Cost and size barriers of Fast Ethernet•

Connector– RJ45 or M12-D•

Cable– Cat5e or above•

Ethernet Hardware––––PHY chipTransformer
EMC protection components
Product connector

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Barriers in EtherNet/IP Protocol Firmware•Network– Barrier: IPv6 Support– Solution: Migrate EtherNet/IP stack to support IPv6; Choose IP stack that can beconfigured to IPv4 only, IPv4 and IPv6, or IPv6 only and support non-OS operation•Transport– Barrier: EtherNet/IP requires TCP while IoT firmware does not require TCP– Solution: Choose TCP/UDP/IP stack that can be configured to UDP-only and Non-OSoperation•

CIP Transport– Barrier: CIP Explicit messages rely on TCP and EtherNet/IP Sessions– Solution: Extend the EtherNet/IP protocol to transport explicit messages over UDP;
The implementation of an EtherNet/IP stack should be scalable for resourceconstrained IoT things

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Agenda•
•
•
•
••
•
•
•

IoT Opportunities for ODVAConstrains of IoT and IIoT Things
Approaches to Connect IoT and IIoT Things to EtherNet/IP SystemBarriers in EtherNet/IP Hardware Interface
Barriers in EtherNet/IP Protocol Firmware
Single Pair Ethernet as a New PHY Layer
UDP-capable Unconnected Explicit Message
Scalable EtherNet/IP StackConclusion

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Introduction of Single Pair Ethernet••

Two versions: 100Mbps and 1Gbps, this paper focus on 100Mbps
Driven by the automotive industry for on-vehicle, then used by multiple industries?
–High volume, low cost, good performance••100Mbps standard target to be published in Aug. 2016Chips already available in market•

15 meters twisted single pair cable with 4 inline connectors–•••••

Specify electronic characteristics, rather than cable and connector

Full-duplex
MASTER/SLAVE
Optional Auto-negotiation of Master/Slave and Speed
Pulse Amplitude Modulation 3 (PAM3) Coding
Lower frequency bandwidth requirement to the communication channel

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Potential Cost and Size Reduction
TX

MAC

EMC

PHYRX

EMC

RJ45or
M12-D

RJ45or
M12-DEMC

RX

PHY
EMC

MACTX

Save size by 50%
Save cost by 40%

MACPHYTechnical Track© 2015 ODVA, Inc.

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2-pin
Conn

EMC

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PHY

MAC

18

Potential Cost and Size Reduction••

Save size by 50%
Save cost by 40%

Two Pin ofMultiple Pins
connector

RJ45 Ethernet
connector

CommonMode Choke

Transformer
Single Pair
Ethernet PHY
Fast Ethernet
PHY
Note: 5 surge protector for Fast
Ethernet in back not shown
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1Pair Power over Data Line (PoDL)•Standard State– Call for Interests in July2013– Task Force approved in Nov2013– D1.2 in review, D2.0 in Nov2015 forWG ballot•

Key Features– 12V for automotive, 24V for industrial;
48V for standard PoE– Up to 10W for 24VDC– <100ms startup time
– No limits on cable and connector

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UDP-capable CIP Unconnected Message•Extend EtherNet/IP to transport unconnected explicit messages over UDP– TCP/UDP/IP stack that can compile TCP off– EtherNet/IP stack that can compile TCP Encapsulation and EtherNet/IP Session
and Class 3 messages off

Transport
EtherNet/IP
Encapsulation

CIP Unconnected
MessageTechnical Track© 2015 ODVA, Inc.

TCP-based CIP unconnected explicit
message
TCP, EtherNet/IP Explicit Port (0xAF12)
SendRRData command (0x6F) over an
EtherNet/IP Session
NULL Address Item (0x00)
Unconnected Data Item (0xB2)
Message Router Request/Response data

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UDP-based CIP unconnected explicit
message
UDP, EtherNet/IP Explicit Port (0xAF12)
SendRRData command (0x6F) without an
EtherNet/IP Session
NULL Address Item (0x00)
Unconnected Data Item (0xB2)
Message Router Request/Response data

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UDP-capable CIP Unconnected Message•Add definition in Capability Flag of ListServices Response– Client chooses UDP/TCP based on this Capability information
Flag Value
Bits 0 - 4Bit 5

Description
Reserved for legacy usage 1
If the device supports EtherNet/IP encapsulation of CIP this bit shall be set (=1);
otherwise, it shall be clear (=0)
Bits 6 - 7
Reserved for legacy usage 1
Bit 8
Supports CIP transport class 0 or 1 UDP-based connections
Bit 9
If the device supports UDP-based CIP unconnected explicit message this bit
shall be set (=1); otherwise, it shall be clear (=0)
Bit 10If the device supports TCP-based CIP unconnected explicit message this bit
shall be clear (=0); otherwise, it shall be set (=1)
Bit 11 - 15
Reserved for future expansion
Table Footnotes
1. Flags marked as “Reserved for legacy usage” indicate flags that were defined prior to thepublication of this specification. Their usage is undefined in this specification. Devices should
not use these flags without prior knowledge of the legacy usage. If a device receives areserved flag that it does not understand, the reply shall be processed and the flag ignored.
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•

ListServices to getServers’ capability

UDP-based CIP Unconnected Explicit
Message Sequence– UDP or TCP or Both•••

No open/close TCP
connection
No register/unregistersession
No communicationbindings, simple forservers

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UDP-based CIP Unconnected Message Sequence forCreating I/O Connections•

ForwardOpen/ForwardClose as special
unconnected messages•

No impact on I/O
connection operation

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Backward Compatibility•

Clients– New clients must support both TCP and UDP methods– A legacy client needs to be updated to support the UDP method•Servers– New servers MUST support at least UDP or TCP method••

New resource-constrained servers ONLY support UDP method
New complex servers may support TCP method, and may support UDP method– A legacy server can operate in a hybrid system without any modifications•Behaviors– Client first retrieves servers’ capability (TCP or UDP) by ListServices– Client chooses the method according to the capability•Client choose TCP if both TCP and UDP are supported– Client may first try TCP and then try UDP without knowing the servers’ capability
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Experimental Results and Wireshark Traffic•

EtherNet/IP Adapter Stack for an embedded device– 2 days to add the feature of UDP-capable unconnected messages for an EtherNet/IPadapter stack (CIP Server and Target)–•

EtherNet/IP Scanner Stack for a PC software– 3 days to add the feature of UDP-capable unconnected messages for an scannerstack (CIP Client and Originator)•Scanner devices can create I/O connections to Adapter devices– Messages are well interpreted by Wireshark•Focus on UDP-capable concept, not IPv6
– Refer to previous papers for IPv6 discussions
https://www.odva.org/Portals/0/Library/Annual-Meeting-2012/2012_ODVA_Conference_XuYuBrooksBatke_FINAL.pdf
http://www.odva.org/Portals/0/Library/Annual_Meeting_2014/2014_ODVA_Conference_Xu_Brooks_Yu_Brandt_CIP_over_6LoWPAN_FINAL.pdf

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Experimental Results and Wireshark Traffic

UDP-based ForwardOpen for
creating I/O connections
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Scalable EtherNet/IP Stack

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Experimental Results for Scalable EtherNet/IP Stack••

30.54% code (38.8Kbytes) and 51.99% RAM (39.3Kbytes) could be saved from“with OS and with TCP” to “without OS and without TCP”
The total UDP-only, Non-OS firmware consumes around 88Kbytes Flash and36Kbytes RAM providing 40Kbytes Flash and 28Kbytes RAM for the application
firmware for a MCU with 128Kbytes flash and 64Kbytes RAM.

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Experimental Results for Scalable EtherNet/IP Stack•

Conditions– Experimental firmware including EtherNet/IP adapter stack, TCP/UDP/IP stack,
OS/Scheduler, HW drivers and an example application– Compiled in release version with medium optimization level– Firmware configuration of “with OS and with TCP” and “without OS and without OS– 3 explicit clients with a maximum 446 bytes explicit message– 4 I/O connections with 18 bytes I/O data
– CIP objects: Identity, Connection Manager, Message Router, Assembly, TCP/IP
Interface, Ethernet Link
Flash (Kbytes)

EtherNet/IP
TCP/UDP/IP
Others
Total
Technical Track© 2015 ODVA, Inc.

W/ OS,W/ TCP
25,95843,64518,65988,262

W/o OS, W/oTCP
32,867
71,68322,513127,063

RAM (Kbytes)

Reduction
21.02%
39.11%
17.12%
30.54%

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W/ OS,W/ TCP
12,847
5,804
17,67736,327

W/o OS, W/oTCP
42,85812,663
20,14875,669www.odva.org

Reduction
70.02%
54.17%
12.26%
51.99%
30

Conclusion•IoT brings opportunities to ODVA to grow its ecosystem•Barriers exist for EtherNet/IP and CIP to connect IoT and IIoT things•Solutions proposed to Barriers– The introduction of Single Pair Ethernet to EtherNet/IP– The introduction of UDP-capable unconnected explicit message to EtherNet/IP– The implementation of scalable EtherNet/IP stack that can be configured to UDPonly for IIoT things

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THANK YOU

Abstract
The Industrial Internet of Things (IIoT) is exploding. The manufacturing enterprise is experiencing theconvergence between Operational Technologies (OT) and Information Technologies (IT). ODVA EtherNet/IP,
using “Unmodified Ethernet” and IP protocol, is a fundamental network infrastructure for this convergence.
Control and supervisory level devices in an industrial automation and control system, such as HMIs,
controllers, drives and I/O modules, have already been connected into the IIoT system via EtherNet/IP. Fieldlevel industrial things, such as sensors, actuators, and process instruments, are being pushed to have
network capabilities to improve the data visibility and operational efficiency of devices, machines andsystems. However these field level industrial things usually have constrained resources, such as limited
computational capability, limited memory, limited communication rate or limited power, and have very low costand small form-factor requirements. Today’s implementations of EtherNet/IP hardware and stack cannot meetthe demands of adding EtherNet/IP connectivity into these resource-constrained industrial things due torequirements for relatively more resources, higher cost and bigger size. This paper examines the potential
EtherNet/IP hardware cost and form-factor reductions with the usage of IEEE standard single pair Ethernet
technology. Detailed analysis shows that the cost and size of the EtherNet/IP hardware and stack could besignificantly reduced. This paper also proposes an extension of UDP-capable unconnected messages to the
EtherNet/IP protocol so that a much simpler UDP-only Ethernet/IP stack implementation that can better meetrequirements of resource-constrained industrial things is accomplishable. With these changes, EtherNet/IP
would be able to be expanded into field level resource-constrained industrial things, enabling a powerful,
totally-connected OT infrastructure for converging with IT and generating innovations of new applications andservices.

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