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I have a few etherCAT devices which each have a slave controller exposing two etherCAT interfaces, and I would like to connect them to the ethernet switch of my home network.

Will I be able to set up an etherCAT master on one of my home computers and communicate with the ethercat devices? Are there any drawbacks if the existing network activity is low?

I would like to use two ports of the ethernet switch to get a ring topology. If necessary, I can connect one end of the ring to a network adapter and the other end to another network adapter, but one of these adapters will be connected to my home network.

Mister Mystère
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  • Redundancy for ecat (ring topology) requires one interface with two transceivers each sending and receiving the same frame, this exotic configuration does not exist on standard switch but only specialty masters with ethercat redundancy interfaces – crasic Sep 22 '21 at 18:48

2 Answers2

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Although EtherCAT uses standard Ethernet hardware it requires a dedicated network - you can't run it directly on an Ethernet network alongside your home network (unlike e.g. Profinet). It does appear that there are EtherCAT to Ethernet adapters available that may do the trick, but I've not had any experience with them.

NMF
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  • This is not entirely true , while a segment (chain) must not be interrupted with a standard Ethernet link, a segment may have a standard and even switched Ethernet link between master and segment start, in this naive topology only one ethercat segment is allowed per switch (because of the fixed Mac address of the input device) but it will route. – crasic Sep 22 '21 at 18:51
  • It must be layer 2 routable, the link between master and ethercat is not ip routed (layer3), but layer 2 (link layer, Mac address), so it must be visible to your masters Ethernet port, so a single switch, hub, or router, will work in theory and occasionally in practice. – crasic Sep 22 '21 at 18:53
  • So are you saying that I can actually connect the ethercat ring to an ethernet switch along with other ethernet devices (since they do not interrupt the master-ethercat chain), as long as the ethernet switch is directly connected to one of the ethernet adapters of the master computer? Is the IP of the ethernet adapter of importance (regarding subnet mask etc.)? – Mister Mystère Sep 22 '21 at 18:55
  • Yes I am saying that in some cases yes this will work, and in theory there are technologies that make this reliable {TSN, ethercatG, and Layer 2 bridges}, but it is better to use a plc or industrial pc for the basic case of segment on a network. – crasic Sep 22 '21 at 18:58
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There area few things here to clarify

Here is the basic ethercat segment (From ETG.1000)

enter image description here

Note that the round trip packet is established via loopback from the last device in the chain, not due from two interfaces.

Loop topology is for redundancy in case of failed node, and requires a specialty interface. This is not required for operation, it is for industrial redundancy.

enter image description here

There are many useful topologies for bridging segments to masters.

In your case you are looking for a single hop bridge. The official solution is to use an Industrial PC (or PLC) that is connected to TCP/IP. You then use other protocols to control the IPC which is running the master software.

(Source: Beckhoff )

enter image description here

Technically, it is not suggested to bridge master and segment with standard ethernet switch. But as long as the Master and slave will see each other in a Layer 2 routable way, they will work and it is worth an attempt. However the performance is not guaranteed.

For higher order technologies there are bridging solutions. For example EtherCAT bridges, EtherCAT-G, and hybrid solutions like TSN networks and Layer 2 VPN.

Suggest also to read free white paper ETG.1600 Installation Guidelines

Usually foots the bill!

enter image description here

crasic
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