Realtime Ethernet concept Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Ethernet as multi-purpose bus TCP/IP Real-time <1ms 10ms 100ms Motion control Field devices Controller and HMI Ethernet communication in automation Coexistent use of realtime and IT communication on one line Uniform realtime protocol for all requirements Scalable realtime communication from high-performance to isochronous Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

OPC-DX Identical for all CPF Modem, ISDN, wireless. ... IEC 61158 & IEC 61784 Ethernet based C. (IEC SC65C Digital Communication) ControlNet/IP PROFInet FF-HSE 1784-1 based Real Time Class 1 ????? CIP Run time; RT-Auto; ACCO FB AP| NMA| MIB SMK User FMS| SMKP| MIB FDA| SNTP|SNMP Application (7) DCOM Transport (4) Encapsulation TCP UDP TCP UDP TCP UDP Network (3) IP IP IP Data Link Layer (2) Modem, ISDN, wireless. ... RealTime Ethernet Class 2 PhLayer (1) IEEE 802.1, IEEE 802.3, IEEE 1588, IEEE 802.x.... Technology specific ISO/OSI Referenz Model Identical for all CPF Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Realtime Ethernet Realtime = deterministic data transmission Ethernet = industrial communication based on IEEE 802 and switching technology Realtime Ethernet (RTE) classes No RTE: no provisions for deterministic communication Low end = Class 1: Cycle times in the range from 5 to 10 msec. Fully compatible with the IP standard and no restrictions on networking components. High end = Class 2: Cycle times in the range from 0,25 to 5 msec. Fully compatible with the IP standard with networking components supporting RTE Option. Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

RTE Class 2 for motion control RTE Class 2 covers the requirements for the motion control applications market segment. RTE Class 2 shall be also fully compatible with the IP standard - with no restrictions. Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Requirements for motion control applications Real-time capability Wood-, glass-and ceramic-processing machines Plastics injection molding machines Packaging machines Printing presses Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Switching technology - the basis for RTE RTE utilizes switching technology: Standard in the office world Prospects for higher data rates A large number of stations Wide network expansion (cascades of 20 or more) Electrical: 100 m per segment FO: 3 km per segment Full-duplex capability Data streams remain local and do not place load on the entire network Simple configuring rules Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Communication architecture with Switch The RTE class 1 and 2 communication - an integrated and scalable solution - 1 2 Open IP channel Device parameterization Reading of diagnostics data Loading of interconnections Negotiation of the communication channel for user data RTE Class 1 channel High-performance transfer Priority Tagging Cyclic data Event-controlled signals RTE Class 2 channel Data in isochronous mode Jitter <1μsec Real-time 3 RTE Cl.1 RTE Cl.2 switch 2 SRT Offener TCP/IP Kanal Geräteparametrierung Lesen von Diagnosedaten Laden von Verschaltungen Aushandeln des Kommunikations- kanals für Nutzdaten Echtzeit Kanal SRT Performante Übertragung Zyklische Daten Ereignisgesteuerte Meldungen 1 Ethernet TCP / UDP Industrial automation applications IT appli- cations e.g. HTTP SNMP DHCP... Standard data Real-time data IP Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

RTE Cl.2 RTE Cl.1 Non RTE Separate track to guarantee realtime Traffic jam RTE Cl.2 jam RTE-Protocol get priority compared to TCP/IP-protocol. In case of a traffic jam, even the class 1 traffic stuck jam RTE Cl.1 Non RTE Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

- separate time domains for real-time and non-real-time - Concept for RTE Class 2 Communication system scheduling - separate time domains for real-time and non-real-time - Open channel (IP) Open channel (IP) RTE channel RTE channel Cycle 1 Cycle 2 Cycle n E.g. 1 ms position control cycle Synchro-nization Deterministic communication Open communication RTE data IP data Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Performance parameters for RTE Class 2 Cycle time Jitter Number of nodes Simultaneously transferable TCP/IP data *) 1 msec <1µsec 35 9 MB/ sec 75 6 MB/ sec 250 µsec 18 *) Standard length of the IP data packets from 64 to 1536 bytes Max. data transmission rate on Fast Ethernet: 12 MB/sec Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Distribution of updating times Occurence n RTE Cl.2 RTE Cl.1 Non RTE 15% 100% t 0.25...1.0 msec 10 msec 100 msec Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Consequences to IEEE 802 Enhancements to the IEEE 802.1D:2003 standard for RTE switched networks : Amend RTE Option In IEEE 802.1D or Specify it separately in IEEE P802.1 or Specify it separately in IEC SC65C. Detailed Concepts will be described in IEC SC65C (IEC 61784-2) Technical topics of the RTE option see next pages Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#

Technical issues on real time switching Synchronized behaviour based on IEEE 1588-Sync Common cycle time Coordinated start of real time schedule Scheduled forwarding Shut down of non real time(RT) processing prior to RT phase Disable non RT forwarding while a port is in RT phase Scheduling list may be used to guarantee precise delivery Coordination of application and communication Ability to run control loops Eliminate jitter of communication cycle by timestamping Fast recovery from communication problems Use redundant paths Include a means for duplication detection Ludwig Winkel, Karl Weber IEEE 802.1 RTE 2004-01-14.ppt P:#