EtherCAT is an open, high performance Ethernet-based fieldbus system. The development goal of EtherCAT was to apply Ethernet to automation applications which require short data update times (also called cycle times) with low communication jitter (for synchronization purposes) and low hardware costs. The EtherCAT protocol is optimised for process data and is transported directly within the standard IEEE 802.3 Ethernet frame using Ethertype 0x88a4. It may consist of several sub-datagrams, each serving a particular memory area of the logical process images that can be up to 4 gigabytes in size. The data sequence is independent of the physical order of the nodes in the network; addressing can be in any order. Broadcast, multicast and communication between slaves are possible. If IP routing is required, the EtherCAT protocol can be inserted into UDP/IP or TCP/IP datagrams. This also enables any control with Ethernet protocol stack to address EtherCAT systems.
Frame 1 (128 bytes on wire, 128 bytes captured) Ethernet II, Src: MS-NLB-PhysServer-14_a6:c9:01:8e (02:0e:a6:c9:01:8e), Dst: Broadcast (ff:ff:ff:ff:ff:ff) EtherCAT frame header .... .000 0111 0000 = Length: 0x0070 .... 0... .... .... = Reserved: Valid (0x0000) 0001 .... .... .... = Type: EtherCAT command (0x0001) EtherCAT datagram(s): 'LRW': Len: 100, Adp 0x0, Ado 0x1, Wc 2 EtherCAT datagram: Cmd: 'LRW' (12), Len: 100, Addr 0x10000, Cnt 2 Header Command : Logical memory read write (0x0c) Index : 0x39 Log Addr : 0x00010000 Length : 100 (0x64) - No Roundtrip - Last Sub Command .... .000 0110 0100 = Length: 100 ..00 0... .... .... = Reserved: Valid (0) .0.. .... .... .... = Round trip: Frame is not circulating (0) 0... .... .... .... = Last indicator: Last EtherCAT datagram (0) Interrupt : 0x0000 Data : 000000000000000000000000000000000000000000000000... Working Cnt: 2
There are no EtherCAT specific preference settings. Allowing sub dissectors to handle data based on heuristic analysis is always enabled and cannot be turned off.
Dissectors that are interested in dissecting the EtherCAT datagram portion of the EtherCAT frame (there may be multiple EtherCAT datagrams in each frame), may do so using heuristic analysis by registering themselves using the function heur_dissector_add("ecat.data", …).
Capture of startup sequence for some Beckhoff devices.
A complete list of IP display filter fields can be found in the display filter reference
Show only the EtherCAT based traffic:
Filter on a specific address offset (ado):
ecat.ado == 0x130
Filter on a specific slave by its position or fixed EtherCAT address (adp):
ecat.adp == 0x3e9
Filter on a specific cmd (here APRD):
ecat.cmd == 0x1
Filter on a specific field of a sub command :
ecat.sub1.idx < 0x80
Show only the EtherCAT mailbox traffic:
Capture Ethercat-over-Ethernet traffic only:
ether proto 0x88a4
Capture Ethercat-over-UDP traffic only:
udp port 0x88a4
More information about EtherCAT can be found on the website of the EtherCAT Technology Group: http://www.ethercat.org/
SOEM (Simple Open EtherCAT Master) can be found at http://openethercatsociety.github.io/
IgH EtherCAT Master for Linux can be found at http://www.etherlab.org/en/ethercat/index.php
Imported from https://wiki.wireshark.org/Protocols/ethercat on 2020-08-11 23:19:43 UTC