Zentralinstitut für Elektronik

Ethernet-based fieldbus functionality for Neutron scattering experiments with

PROFINET IO

H. Kleines, S. Detert, F. Suxdorf, M.DrochnerZentrallabor für Elektronik (ZEL), Forschungszentrum Jülich

– Jülich Center for Neutron Science (JCNS)– PROFINET CBA– PROFINET IO– Application to Neutron Scattering

Zentralinstitut für Elektronik

Jülich Centre for Neutron Science JCNS• JCNS founded after shutdown of FRJ-2 in May 2006• Branchlabs in Garching (FRM-II), Oak Ridge (SNS)

and Grenoble (ILL)• 8 experiments being built at FRM-II (30 new staff

members)• “Jülich-Munich Standard”

– TACO– Linux– Python– S7 PLCs– PROFIBUS

Zentralinstitut für Elektronik

Example: Small Angle Scattering KWS2

ET-200S

Simatic S7 300mit IM 360 und IM361

auf zwei Profilschienenverteilt

1A1

1A1

1A1

19 pneumatik Zylinder mit

Endlagenschalter

7 Kollimationsblendenje 2 Motore

Secondary PROFIBUS-DP

JuDiDT

PROFIBUS-DPControl Server Detektor Server

19" EinschubCPCI1

LinuxTACO-Server

FRM II-Netz (TCP/IP)

Multiplexer

Steppercontroller

MonitorZähler

Fiber

Probentisch Detektorantrieb

DrehgeberProbenblende

1A1

1A1

1A1

1A1

1A1

1A1

StatusDisplay

Ortsauflösender Detektor

Touch PanelVakuum und

Strahlschieber

Aktor Sensor Interface

DP/DP Coupler

28 Endschalter der Kollimationsblenden

PhysikrechnerLinux

TACO-Client mit PSH

Fileserver

CPCI2

5 Vakuum Meßröhren

CAN Proben-

umgebung(Julabo,

Eurotherm)

1A1

1A1

1A1

Ventile Strahlschieber Vakuumschieber

Zentralinstitut für Elektronik

Motivation• Connection of process equipment to server computer:

PROFIBUS DP• Problem:

– Controller availability for cPCI/Linux– Continuous device driver modifications

• Possible solution: Ethernet• Problem:

– Missing Application Layer– Inappropriate for the factory floor (RT features, noise, etc.)

• Several initiatives during the last years– Ethernet/IP (Allen Bradley)– Modbus/TCP (Schneider)– Powerlink (B&R)– EtherCAT (Beckhoff)– PROFINET (PNO, Siemens): PROFINET CBA and IO

Zentralinstitut für Elektronik

PROFINET CBA Model• Uniform approach to engineering, data transfer and

diagnosis• Open, vendor-independent communication based on

Ethernet + TCP/IP (IEC 61784-1)• Object-oriented component-based model supporting

modularization of an automation system• Automation system is subdivided into autonomous

components, described by interface variables

Technological module(Mechanics +Electronics+Software)

Zentralinstitut für Elektronik

CBA Engineering

Configuration Programming Component Generation

Machine manufacturer A

Configuration Programming Component Generation

Machine manufacturer B

Vendor-specific configuration and programming tools

Vendor-independent XML-file

Zentralinstitut für Elektronik

CBA Connection Editor

Filling Bottle cleaning

Download of interconnection info

Import

• Vendor independent tool• Imports XML-files• Definition of Interconnections• Download of Interconnections• Diagnostics

Interconnection info:• Communication partners• Communication relationships• Information to be exchanged• Update cycle, etc.

Zentralinstitut für Elektronik

PROFINET CBA Communication

• Transparent PROFIBUS integration with proxies• Runtime model:

– device = collection of COM objects => DCOM– automatic data transfer by PROFInet Kernel

• DCOM/TCP/IP can be bypassed by Soft Real Time Stack• Free source code available for PNO members

Ethernet

IP

TCP

DCOM

PROFInet Kernel

Real Time Data

Application

3

4

7

2PROFIBUS

Ethernet

Proxy

Zentralinstitut für Elektronik

PROFINET IO Model• Designed in 2003 by PNO as supplement to PROFINET CBA

(hidden in a component) – will be included in IEC61874-2• Aims at decentral periphery scenarios with cyclic data exchange• Closely resembles PROFIBUS model and operation• 3 categories of stations (master/slave scenario):

– IO controller: typically a PLC– IO device: subordinate field device– IO supervisor: typically an engineering station

Zentralinstitut für Elektronik

IO Device Model• (Potentially) modular device model• Slot/Subslot: Common addressing scheme for data, alarms and

diagostic information• GSD-File defines device features (modular structure, parameters)• Engineering tool imports GSD files:

– Offline Device configuration and parameterization– Downloads configuration to IO controllers

Slot 0 Slot 1 Slot 2 Slot 3

Bus interface

Subslot 0

Subslot 1

Subslot 2

Subslot 0

Subslot 1

Subslot 0

Subslot 1

Subslot 2

Zentralinstitut für Elektronik

PROFINET IO Operation• Strict sequence of phases:

– IP address assignment via discovery and control protocol (DCP)– Establishment of application relation and subordinate

communication relations via context management services– Configuration and parameterization of all IO devices via the

acyclic record data services– Entering the cyclic data exchange mode (process data +

alarms)

IO device

IO controller

Application Program

Asynchronous Access Process

Image Inputs

Process Image

Outputs

Cyclic update

PROFINET

Zentralinstitut für Elektronik

PROFINET IO communication• Non-RT communication (Context

Management, acyclic record data)• RT communication

– for cyclic data exchange (and DCP)– bypasses (optionally) UDP/IP – ethertype 0x8892

• Isochronous RT communication– Jitter of bus cyle time duration below

1µs– Employs PTCP (Precision

Transparent Clock Protocol) according to IEC61158

– Requires ASIC support• Special connectors for IP20 and

IP65 (optionally with power)• ASIC with integrated switch allows

bus-like topologies

Ethernet

IP

UDP

Connectionless RPC

PROFInet IO

Application

3

4

7

2

Non-RT RT

Zentralinstitut für Elektronik

PROFINET IO at JCNS• PROFINET IO much simpler than CBA• Similar to PROFIBUS => fits into existing framework• Well-supported by S7-300 PLCs and ET200S• PLC programming almost identical to PROFIBUS DP=> Decision: Adopt PROFINET IO as an optional replacement for

PROFIBUS DP• Problem: Linux-Support

– Avoid communication controllers (also not avail. for cPCI)– Source Code available for IO device but not for IO controller

=> Start implementation of PROFINET IO controller subset under Linux