I apologize if my query id off-topic here, as I could not find a suitable newsgroup to post to. I am interested in the details of the frame structure of the EtherCAT protocol. I visited
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, but the documentation there is very high level. I understand the algorithm very well, but I have some questions regarding the Ethercat frame structure. I am doing my PhD in electronics, and wish to implement this protocol on some embedded devices (motes). Given that the protocol typically runs over a network with a master and several slave devices, and that the EtherCAT frame is a basically an Ethernet frame with a different payload, but same header,- What are the destination and source MAC addresses in the Ethernet frame -- given that now each slave device in the network will receive the same EtherCAT frame, and all EtherCAT data/information is the EtherCAT specific payload. Basically what destination address does the master put in the Ethernet header of an outgoing frame -- maybe its own so that the last slave device can create a frame to the master. Or does the master send out the frame with the MAC address of the last slave device ?
- Each EtherCAT frame consists of an EtherCAT frame and the PDO and the WC ('working counter' ) What exactly is this, and why is it there ?
Any hints/suggestions or pointers to documentation would be greatly appreciated. I apologize once again, if this is off-topic here.