EtherCAT Master. Dipl.-Ing. (FH) Florian Pose. EPICS Collaboration Meeting, Lund May 25th, Ingenieurgemeinschaft IgH. EtherLab s Open-Source

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1 s s Dipl.-Ing. (FH) Florian Pose Ingenieurgemeinschaft IgH EPICS Collaboration Meeting, Lund May 25th, 2016 Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 1 / 26

2 Outline s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 2 / 26

3 Characteristics of EtherCAT Advantages Ethernet-based High bandwidth (10 khz with 100 servo axes) Less overhead (summing frame, single master) Flexible topologies (physical) Logical ring structure (realtime capable) Open standards (ETG, IEC type 12, IEEE 802.3, etc.) Cheap hardware (at least master and cabling) s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 3 / 26

Frame processing on the fly s Source: http://ethercat.org Rev.

4 Frame processing on the fly s Source: Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 4 / 26

5 Features of EtherCAT Synchronisation via Distributed Clocks (DC) Redundancy via multiple Ethernet links Mailbox protocols (... over EtherCAT) CANopen protocol (CoE) Sercos profile (SoE) Ethernet (EoE) File-access (FoE) Vendor-specific (VoE) Functional safety over EtherCAT (FSoE) Diagnosis via standard tools s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 5 / 26

6 Characteristics of EtherCAT (2) s Disadvantages Special (intelligent) slave hardware required Complex technology Interfering features Redundancy not foolproof Wrong endianess Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 6 / 26

7 Outline s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 7 / 26

8 s ( is an open-source automation toolkit covering several components: EtherCAT master MATLAB/Simulink blocks for EtherCAT Process data access and visualisation libraries Data-logging services Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 8 / 26

9 References Airbus High-Lift Testrigs s Neumayer Station, Antarctica Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 9 / 26

10 Software Distribution Mercurial-Repository etherlabmaster Branches: default Development (unstable) stable-1.5 Current stable version Tarballs and Documentation Software components EtherCAT master Mailing lists s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 10 / 26

11 s Reference implementation for Windows supplied by Beckhoff Alternative: Linux Complete control over OS kernel Open source Full-featured operating system No license costs Realtime extensions Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 11 / 26

12 General Features s Implementation from scratch acc. to IEC Kernel modules and userspace libraries for Linux 2.6 and later Master licenced under GPLv2; userspace library under LGPLv2 Several masters can co-exist on the same host Optimized performance (e. g. no unnecessary copy operations in realtime context) and robustness Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 12 / 26

13 Userspace Kernelspace Hardware Architecture 'ethercat' Tool Network Stack Generic Ethernet Driver Module Packet Socket Generic Ethernet Device netif_*() net_device Standard Ethernet Driver EtherCAT NIC net_device libethercat Application Interface ecrt_*() Userspace Application libethercat_rtdm Application Interface ecrt_*() LXRT / Xenomai Userspace Application Character Device RTDM Device Module Master 1 Application Interface ecrt_*() Kernelspace Application Module Master 0 Task Device Interface ecdev_*() Native EtherCATcapable Ethernet Driver net_device Ethernet NIC EtherCAT NIC

14 Master phases s Device connection Master request Orphaned Idle Operation Device disconnection Master release Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 14 / 26

15 Native s EtherCAT-capable versions of standard Linux Ethernet drivers Realtek drivers 8139too and r8169 Intel drivers e100, e1000 and e1000e Beckhoff CCAT FPGA Interrupt-less operation (deterministic cycle) Porting of further drivers due to common device interface Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 15 / 26

16 Generic Ethernet Driver s Covers all chips supported by the Linux kernel Uses the lower layers of the Linux network stack Not usable with certain realtime extensions (RTAI etc.) Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 16 / 26

17 Realtime Extensions s Supports any Linux realtime extension due to an independent architecture RTAI, Xenomai, RT-Preempt, etc. Operation possible even without realtime Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 17 / 26

18 s Common C/C++ interface for EtherCAT applications Kernel- and userspace (same header ecrt.h) Master management (requesting / releasing) Bus information Slave configuration Cyclic operation Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 18 / 26

19 Domains s Partitions of the process data image Handling slaves with different sample times Monitoring of process data exchange Dynamic slave handling Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 19 / 26

20 Finite State Machine Every master runs a finite state machine in process context, that has the following tasks: 1. Bus scanning Started after each topology change 2. Slave configuration Automatic configuration of slaves (after request) 3. Request processing Handling of external requests 4. Bus monitoring Slave states are cyclically queried s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 20 / 26

21 Ethernet over EtherCAT s Implementation of the Ethernet over EtherCAT (EoE) mailbox protocol Tunnelling of Ethernet traffic via the EtherCAT bus Virtual network interfaces for all EoE-capable slaves Both a switched and a routed topology are natively supported (configurable via standard system tools) Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 21 / 26

22 Userspace Command-line tool ethercat (this will be your friend) Information about masters, slaves, domains, configurations, process data, etc. E 2 PROM access and alias addressing Parameter and file transfers Physical memory access Controlling application-layer states Generation of slave information in several formats (C-code, XML, MATLAB, DOT language) s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 22 / 26

23 System Integration s Seamless integration in arbitrary GNU/Linux distributions Linux Standard Base compatible init script / systemd service file for inserting the master as a system service Configuration of master via a sysconfig file / ethercat.conf Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 23 / 26

24 Outline s Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 24 / 26

25 Future Features s Improve mailbox handling Improve scanning performance Update of native drivers Version in 2016 Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 25 / 26

26 Tack så mycket s Thank you very much for your interest! Rev. fde55f3b904c, May 24, 2016 Ingenieurgemeinschaft IgH 26 / 26

IgH Master Documentation

IgH Master Documentation IgH Master 1.5.0 Documentation Dipl.-Ing. (FH) Florian Pose, fp@igh-essen.com Ingenieurgemeinschaft Essen, April 30, 2010 Revision 6129a5f715fb ii 6129a5f715fb, 2010/04/30 Contents Conventions....................................