Advantech PCIE-1203 User Manual page 9

Figure 1.2 EtherCAT Protocol
EtherCAT datagrams are processed before receiving the complete frame.
In case data is invalid, the frame check sum (FCS) is not valid and the slave will not
set data valid for the local application.
1.1.1.3 Topology
EtherCAT supports a variety of network topologies, including line, tree, ring and star.
The line and tree topologies are more conducive to fieldbus applications because
they require fewer connections and utilize a much simpler and more flexible cabling
schema that switches and hubs are not necessary for lines or trees topology.
Figure 1.3 EtherCAT Topology
Inexpensive industrial Ethernet cables up to 100m apart, can be used between two
nodes in 100BASE-TX mode. EtherCAT makes a pure bus or line topology with hun-
dreds of nodes possible without limitations. Up to 65,535 devices can be connected
to EtherCAT, so network expansion is almost unlimited.
EtherCAT supports individual nodes to be connected and disconnected during opera-
tion. If one of the slaves in the network is removed, the rest of the network can con-
tinue to operate normally. Additionally, EtherCAT also enables other communication
features such as cable redundancy or even master redundancy with Hot Standby.
3 PCIE-1203 User Manual