Beckhoff real time Ethernet 1 RV 20 02

Beckhoff real time Ethernet 1 RV 20. 02. 2021

Ethernet top down the I/O level One fieldbus technology for every need Benefits: • consistent communication • simple to install • independent system • access to each production data • standard Ethernet protocol • competitive and powerful network • bandwidth: from 100 MBaud to 1 Gigabit 2 RV 20. 02. 2021

Real time Ethernet requirements • cycle times of 1 ms and less • high data flow • deterministic and real time capable • cyclic communication of process data • acyclic communication of parameter data • simple vertical integration • flexible topology • cost-saving 3 RV 20. 02. 2021

Ethernet and real time? Hard- and software requirements Hardware: • No, if CSMA/CD with 10 or 100 MBaud duplex and/or Hubs are in use • Yes, if 100 MBaud full-duplex are in use – with switches (RTEthernet) or without (Ether. CAT) Software: • No, if TCP/IP Stacks (of standard operating systems or RTOS) are in use • Yes, if the protocol is used directly within the Ethernet frame of RTOS (e. g. Twin. CAT). 4 RV 20. 02. 2021

First Beckhoff solution: RT-Ethernet real time Ethernet driver („Y-driver“) supports Windows 2000/XP standard Ethernet as physical medium full-duplex communication: no hubs but switches required only standard network components parallel transport of other Ethernet protocols is possible high performance (comparable with Powerlink) cost-effective available since 2002 Beckhoff Ether. CAT 22 Bytes Ethernet-Header (MAC-ID) 88 -A 4 • • 5 RV 46. . . 1500 Bytes Ethernet-Data CRC 20. 02. 2021

Second Beckhoff solution: Ether. CAT OS independent real time Ethernet (Twin. CAT: Windows 2000/XP) standard Ethernet as physical medium communication also possible without switches (no hubs) master: standard network components, slaves: ASIC/FPGA parallel transport of other Ethernet protocols is possible extreme high performance (> 10 times faster) und synchronous simple and most flexible topology even more cost-effective open technology, supported by the Ether. CAT Technology Group 2004: pilot installation, 2005 launch to opening up of new markets 22 Bytes Beckhoff RTEthernet-Header (MAC-ID) 46. . . 1500 Bytes Ethernet-Data 88 -A 4 • • • 6 RV CRC 20. 02. 2021

Y-driver for RT-Ethernet + Ether. CAT Twin. CAT I/O with real time Ethernet driver • communication in hard real time • if it is possible, controlling of operating system Ethernet traffic Windows Twin. CAT TCP/IP I/O System (original Windows Stack) NDIS Protocol NDIS Miniport Twin. CAT I/O Ethernet Controller 7 RV Process Images Ethernet Controller e. g. Profibus Master 20. 02. 2021

RT-Ethernet + Ether. CAT: Direct Memory Access is saving time for the master Traditional PC control hardware IPC Hardware Feldbus Karte Fieldbus cards • communication via the CPU and PCI bus • the transfer of the PC RAM is using the CPU • this requires 20 to 30% of the CPU performance Ethernet cards • Twin. CAT RT Ethernet IO + Ether. CAT are using the DMA controller to transfer the process data 8 RV DP RAM PCI bus CPU PC RAM IPC Hardware Ethernet Karte CPU PC RAM PCI bus DMA NIC card 20. 02. 2021

RT- Ethernet configuration I • IPC with standardised Intel based adapters • cascaded switches can be used • up to 100 m with 100 Base-Tx • standard fast Ethernet 100 Mbit/s with Cat 5 e cable (Shielded Twisted Pair) • standard RJ 45 connectors Windows 2000/XP Standard Netzwerk Adapter Switch I/O (BK 9000) Benefit only standard Ethernet components in use Drives 9 RV 20. 02. 2021

RT- Ethernet configuration II Windows 2000/XP Standard Network Adapters Using hard real time: communication with the office network via a second network card Windows 2000/XP Standard Network Adapter office/company network Switch Windows 2000/XP Switch Standard Netzwerk Adapter I/O (BK 9000) network variables / ADS I/O (Drives) 10 Embedded PC (CX 1000) RV 20. 02. 2021

PC-PC communication with RT-Ethernet Network variables § Publisher/Subscriber model with • Broadcast • Multicast • Unicast § reaction time of PC ↔ PC Ethernet communication < 1 ms § Ethernet type: as Ether. CAT § protocol: RT-Ethernet, like Ether. CAT Variable n Variable 1 publisher / subscriber 11 RV subscriber publisher 20. 02. 2021

Characteristics of RT-Ethernet § Standard Fast Ethernet: • cost-effective network components • cable • connectors § easy to install § Windows conform drivers § software based solution, no special hardware required § transmission time of I/Os < 60 µs § cyclic I/O and standard TCP/IP parallel with the same hardware (Y-driver) § deterministic PC-PC communication via the Ethernet 12 RV 20. 02. 2021

RT-Ethernet: Update time 18µs Ethernet Frame Node 1 n * 18µs Ethernet Frame Node n - all Ethernet Frames are sent successively without waiting of the reply from the slave. - an Ethernet frame of 160 Byte (witch means about 140 Byte reference data) needs per frame about 18 µs to leave the Ethernet port. 13 RV 20. 02. 2021

RT-Ethernet: Update time - the frames are received and transferred via the switch to the devices - the delay in-between receiving and transferring can be 10 to 300 µs depending on the switch and the amount of transferred data 14 RV 20. 02. 2021

RT-Ethernet: Update time The internal bus cycle is getting activated, after the frame reached the coupler. The reply is send back only when all entering data are updated and available. 15 RV 20. 02. 2021

RT-Ethernet: Updatezeiten n * 16µs Ethernet Frame Box 1 response Ethernet Frame Box n It is possible, that some frames of connected devices already reach the mast even if not all have been send. This is possible because: 1. Ethernet full duplex, viz sending and receiving at the same time 2. The data are getting buffered and switch controlled send 16 RV 20. 02. 2021

RT-Ethernet: Update time 160 Byte Ethernet Frames with 140 Byte in- and output data, 60 slaves, 100 Mbaud, 1, 5 ms K-Bus 18 µs * 60 Slaves = 1080 μs K-Bus 1. Slave request K-Bus 60. Slave 18 μs response Ca. 1500 μs 17 RV In comparison with Lightbus: 105 ms x 2 = 210 ms PROFIBUS 12 Mbaud: 18 ms x 2 = 36 ms 20. 02. 2021

RT-Ethernet: Update time PLC-Task RTEthernet K-Bus output data 20 Byte in- and output reference data 4, 5 μs input data synchronized bus system (Lightbus, PROFIBUS) output data input data 18 RV 20. 02. 2021

Update-, Cycle- and Reaction time Beckhoff Twin. CAT / RT Ethernet I PLC Task O I PLC O I I PLC O PLC Task O II PLC Task OO PLC Task O I PLC O I Ethernet Delay TI/O TI/O best case Time worst case Reaction Time Input (Worst case) (Best case) Output TI/O Bus Update Time TI/O Bus Cycle Time Tmdv: Master Processing Delay TI/O: Local I/O Update Time (Firmware) 19 RV 20. 02. 2021

Reaction time measuring of RT-Ethernet Input signal worst case 2, 4 ms Input filter Task: 1 ms Output signal I/O-Bus best case 1, 4 ms Bus System RT Ethernet Task Cycle 1 ms Bus Mode polling Baud rate 100 MBaud Master Sync yes Slave Sync yes Input filter 0, 2 ms Jitter 1 ms Jitter = Task Cycle! grid 0, 4 ms 20 RV 20. 02. 2021

Comparison of the reaktion times Lightbus Profibus Synchroner Mode RT-Ethernet Task time 4 Task cycles 2 Task cycles Run time of one cycle with 60 Slaves and 140 Byte reference data per slave 126 ms 20 ms 2 ms without KBus With K-Bus Update Max 2 ms plus KBus update time sum 4 * 126 ms = 504 ms 4 * 20 ms = 80 ms 2 * (2 ms +3 ms K -Bus) = 10 ms 21 RV 20. 02. 2021

Advantages of RT-Ethernet in comparison with other fieldbus systems - no special fieldbus card required (less costs) - flexible in the connection with standard Ethernet component - LAN - WLAN - fibre -… - high transfer rate - fast reaction time of the whole system - The usage of the DMA controller is saving CPU performance, which can be used for other applications 22 RV 20. 02. 2021

RT-Ethernet: component - AX 2000 -B 900 - typical response time 250 µs - BK 9000 - typical response time 1 - 3 ms - BK 9100 - typical response time 1 - 3 ms - IL 230 x-B 900 - typical response time 1 - 5 ms (because up to 120 IE – modules are possible) - CX 1000 - typical response time 1 ms 23 RV 20. 02. 2021

The development from the beginning to Ether. CAT communication via TCP/IP or UDP/IP e. g. Modbus. TCP, ADS, …. - no real time - cycle time of 2 – 50 ms - no special hard- or software required RT-Ethernet - hard real time - cycle time of 1 ms - Twin. CAT I/O and Intel Ethernet Chip - hard real time - cycle time < 100 μs - Beckhoff implementation: Twin. CAT I/O and Intel Ethernet Chip Ether. CAT 24 RV 20. 02. 2021