Single Wire Coexistence ofsercos and EtherNet/IP
Ludwig Leurs
Bosch Rexroth
Technical Trackwww.odva.org

Single Wire Coexistence ofsercos and EtherNet/IPOutline
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History
New requirements
Targets
Topology
Structure of communication cycle
Ethernet advantages
Why EtherNet/IP and sercos?
Application Scenarios
Verification

Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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History
Single Wire Coexistence ofsercos and EtherNet/IP

All fieldbusses migrate to Ethernet• Increases speed & reduces number of cabling systems



CIP covers several physical layers and has
defined support of bridging and routing
sercos• Was introduced for usage in digital drives• Focused on closed loop control, synchronization, uses
TDMA
• sercos III– Uses Industrial Ethernet keeping the TDMA principle– Real time Ethernet is kept separate from standard
Ethernet– Standard Ethernet used for commissioning and diagnosis

Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
New requirements


Safety of machinery• Use standard network interface• Reduce cost of– Implementation (common stack)– Test (common tools)– Certification (process, tools)• Leads to advantages for– Vendors– OEM– End users

Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IPTargetsIndustrial Ethernet system use the same physicallayer• Not all systems can coexist in one network– Full/half duplex issues– Different time synchronization methods– Conflicting priorities



Targets for EtherNet/IP and sercos• Reduce complexity• Reduce costs• Extend variety of usable productsTechnical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Topology of sercos I & II
Target: machine tools
Fiber optic ring

Sercos MasterSingle fiberNo redundancy
High noise immunity
MMM

Servo drives
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Topology of sercos III
Target: all machinesEthernet 100Mbps, full duplex

Sercos MasterBoth directions
Hot plug extensible

MM

M

Servo drives
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

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Single Wire Coexistence ofsercos and EtherNet/IP
Topology of sercos III
Target: all machinesEthernet 100Mbps, full duplex

Sercos MasterBoth directions
Hot plug extensible
Media Redundancy
MMM

Servo drives
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

page 8www.odva.org

Single Wire Coexistence ofsercos and EtherNet/IP
Topology of sercos III
Target: all machinesEthernet 100Mbps, full duplexSercos MasterBoth directions
Hot plug extensible
Media Redundancy
MMM

Servo drives
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

page 9www.odva.org

Single Wire Coexistence ofsercos and EtherNet/IP
Structure of communication cycle
MDT0HMD S
R TAT0MDT0HMD SR TH S
D 3
R Ht6t7tcycsercos
Ethertype = 0x88CD

Unified Communication
Ethertype ≠ 0x88CD

MDT: Master Data Telegram
HDR: Header
MST: Master Sync Telegram, timing precision depends on master,compensated for slave ordertcyc: cycle time
AT: Answer Telegram
S3H: sercos III header
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

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Single Wire Coexistence ofsercos and EtherNet/IP
Structure of communication cycle
MDT0 MDT1 MDT2 MDT3HM
D SR TH
DRH
DRHDR

AT0H
DRAT1AT2AT3

MDT0H
DRHDRHDRHM
D SR Tsercos
Ethertype = 0x88CD

Unified Communication
Ethertype ≠ 0x88CDExamples
 Only MDT0 and AT0: up to 70 sercos III devices using 250µs;
cycle time 1ms leaves 750µs for EtherNet/IP (≈ 37 devices) 64 sercos III devices with 2ms cycle time and 400µs sercos timeslot
 leaves 1600µs for EtherNet/IP (≈ 80 devices)
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

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Single Wire Coexistence ofsercos and EtherNet/IPEthernet advantages
Common cabling
Increased data rate
Network connectivity using standardizedprotocols
Integrate non-sercos devices• e.g. barcode reader

Direct commissioning access
Remote diagnostics to field device
Extended application coverage by integrating newdevices

Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Why EtherNet/IP and sercos


Wide choice of EtherNet/IP products
CIP is designed for internetworking
CIP is designed in an object oriented way straightfrom the beginning
EtherNet/IP is fairly easy to implement
EtherNet/IP stack has a relatively small footprint
EtherNet/IP is proven technology
sercos and EtherNet/IP share the “CIP Safety”
common safety protocol

Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Examples for SWC
Motion Logic
Control / PLC
Dual Stack Master

EtherNet/IP
OriginatorStandardI/OMM

Servo drives

SERCOS III devices
Technical Track© 2012 ODVA, Inc.

Line topology

Standard
I/O

M

BarcodeScannerFrequency
converters
Ethernet/IP devices
2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Examples for SWC
Motion Logic
Control / PLC
Dual Stack Master

EtherNet/IP
OriginatorStandard
I/O

M

M

Servo drives

SERCOS III devices
Technical Track© 2012 ODVA, Inc.

Ring topology

Standard
I/O

M

BarcodeScannerFrequency
converters
Ethernet/IP devices
2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

page 15www.odva.org

Single Wire Coexistence ofsercos and EtherNet/IP
Examples for SWC
Motion LogicControl

PLC

Dual Stack MasterLine topology

EtherNet/IP
Originator

SSSM

SStandard
I/OM

Servo drives

SERCOS III devices
Technical Track© 2012 ODVA, Inc.

Standard
I/O

M

Laser
ScannerFrequency
converters
Ethernet/IP devices
2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Proof of Concept

Criteria• No timeout of EtherNet/IP connections• No broadcast conflicts• Limits only by bandwidth or controller capacityAdditional requirements• Predetermined number of devices at configuration stage• Common physical layer cabling rules

Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Basic configuration
trace
sercos III drives

EtherNet/IP III drives

EtherNet/IP I/O systems
sercos III time slots
EtherNet/IP standard Ethernet

IP switch
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Extended configuration

EtherNet/IP I/O systems

sercos III drives

Technical Track© 2012 ODVA, Inc.

EtherNet/IP III drives

2012 ODVA Industry Conference & 15th Annual Meeting
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Single Wire Coexistence ofsercos and EtherNet/IP
Results

Criteria• No timeout of EtherNet/IP connections– Changes in sercos startup• No broadcast conflicts– Changes in end of line behavior• Limits only by bandwidth or controller capacity
Additional requirements• Predetermined number of devices at configuration stage– Excel sheet• Common physical layer cabling rules– No conflicts
Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

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Single Wire Coexistence ofsercos and EtherNet/IPSummary

EtherNet/IP and sercos can coexist in a blended
network
EtherNet/IP is the best choice for adding devices
in the Unified Communication channel
Market extension• EtherNet/IP devices can be operated by asercos/EtherNet/IP dual stack master• sercos motion applications can access the huge variety of
EtherNet/IP devices

Limits: CIP sync and CIP motion are currently notsupported

Technical Track© 2012 ODVA, Inc.

2012 ODVA Industry Conference & 15th Annual Meeting
All rights reserved.

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