Realtime Ethernet concept Ludwig Winkel Karl Weber IEEE

Realtime Ethernet concept Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 1

Ethernet as multi-purpose bus Controller and HMI 100 ms Field devices Motion control 10 ms <1 ms TCP/IP Real-time Ethernet communication in automation l Coexistent use of realtime and IT communication on one line l Uniform realtime protocol for all requirements l Scalable realtime communication from high-performance to isochronous Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 2

OPC-DX User Application (7) Transport (4) Real Time Class 1 Control. Net/ IP CIP Data Link Layer (2) Ph. Layer (1) ISO/OSI Referenz Model PROFInet Run time; RT-Auto; ACCO ? ? ? DCOM FF-HSE 1784 -1 based FB AP| NMA| MIB SMK FMS| SMKP| MIB FDA| SNTP|SNMP Encapsulation TCP Network (3) IEC 61158 & IEC 61784 Ethernet based C. (IEC SC 65 C Digital Communication) IP UDP TCP UDP IP Real. Time Ethernet Class 2 Modem, ISDN, wireless. . IEEE 802. 1, IEEE 802. 3, IEEE 1588, IEEE 802. x. . Technology specific Identical for all CPF Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 3

Realtime Ethernet l. Realtime = deterministic data transmission l. Ethernet = industrial communication based on IEEE 802 and switching technology l. Realtime l. No Ethernet (RTE) classes RTE: no provisions for deterministic communication l. 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. l. 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: # 4

RTE Class 2 for motion control l RTE Class 2 covers the requirements for the motion control applications market segment. l 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: # 5

Requirements for motion control applications Real-time capability Wood-, glassand ceramicprocessing machines Plastics injection molding machines Packaging machines Printing presses Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 6

Switching technology - the basis for RTE utilizes switching technology: l Standard in the office world l Prospects for higher data rates l A large number of stations l Wide network expansion (cascades of 20 or more) Electrical: 100 m per segment l FO: 3 km per segment l l 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: # 7

Communication architecture with Switch è The RTE class 1 and 2 communication - an integrated and scalable solution - 1 Open Offener IP TCP/IP channel. Kanal l IT applications l l l 1 Standard data Real-time data TCP / UDP 2 RTE Echtzeit Class Kanal 1 channel SRT IP 2 Ethernet switch l Real-time e. g. l HTTP l SNMP l DHCP. . . Industrial automation applications Device parameterization Geräteparametrierung Lesen von Reading of Diagnosedaten diagnostics data Laden von Loading of Verschaltungen interconnections Aushandeln of Negotiation des the Kommunikationscommunication channel for kanals user data für Nutzdaten l SRT 2 RTE 3 RTE Cl. 1 Cl. 2 Real-time l l High-performance Performante Übertragung transfer Zyklische Priority Tagging Daten Ereignisgesteuerte Cyclic data Meldungen Event-controlled signals 3 RTE Class 2 channel l High-performance transfer Data in isochronous mode Jitter <1μsec Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 8

Tr jam affic Separate track to guarantee realtime jam RTE-Protocol get priority compared to TCP/IP-protocol. jam RTE Cl. 2 In case of a traffic jam, even the class 1 traffic stuck RTE Cl. 1 Non RTE Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 9

Concept for RTE Class 2 è Communication system scheduling - separate time domains for real-time and non-real-time - Open channel (IP) RTE channel Cycle 1 Open channel (IP) RTE channel Cycle 2 Cycle n E. g. 1 ms position control cycle Synchronization Deterministic communication RTE data Open communication IP data Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 10

Performance parameters for RTE Class 2 Cycle time 1 msec 250 µsec Jitter <1µsec Number of nodes Simultaneously transferable TCP/IP data *) *) 35 75 18 9 6 6 MB/ sec 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: # 11

Distribution of updating times Occurence n RTE Cl. 2 RTE Cl. 1 15% 0. 25. . . 1. 0 msec 10 msec Non RTE 100% 100 msec t Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 12

Consequences to IEEE 802 Enhancements to the IEEE 802. 1 D: 2003 standard for RTE switched networks : 1. Amend RTE Option 1. In IEEE 802. 1 D or 2. Specify it separately in IEEE P 802. 1 or 3. Specify it separately in IEC SC 65 C. 2. Detailed Concepts will be described in IEC SC 65 C (IEC 61784 -2) 3. Technical topics of the RTE option see next pages Ludwig Winkel, Karl Weber IEEE 802. 1 RTE 2004 -01 -14. ppt P: # 13

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: # 14