EtherCAT coupler port allocation

The data flow direction in an EK1000 is shown as an example in the following figure:

Frame processing sequence

• The incoming Ethernet frame at the Ethernet signal input is forwarded to the internal EtherCAT Open Mode port.
• Destination and source addresses are swapped or replaced (for MAC and IP/UDP, if applicable).
• The EOM frame arrives at Port 0 (A) and the data frame departs via Port 0 (A) to the following slave in the EtherCAT terminal network (if a slave is connected there and an active link is detected).
• After the arrival of the data frame at Port 1 (B) from the terminal network, this is forwarded and leaves the coupler at the following EtherCAT output (if a slave is connected there and an active link is detected).
• The data frame arrives at Port 1 (B). This is now forwarded to the EtherCAT Open Mode port and leaves the EK1100 via the Ethernet input.