
SFA-5000 • SFA-10000 EtherCAT
6 - EtherCAT® interface
6.1 Basic Information on the EtherCAT® Protocol
The EtherCAT protocol is designed to use the standard Ethernet dataframes for
issuing data; in addition, and as regards the hardware, it is not necessary to
install dedicated Masters for establishing and managing the EtherCAT
communication because standard Ethernet network cards can be used. This
results in a great advantage in terms of lower costs and simplicity of use
because Ethernet network cards are used in standard personal computers and
are easily commercially available.
An EtherCAT bus can be viewed as a single and large Ethernet device that
receives and sends Ethernet telegrams; it can be considered an Ethernet subnet
supported by an Ethernet dataframes structure.
However this “subnet” must be fitted with one only EtherCAT Master controller
and several EtherCAT Slaves, but no Ethernet controller with downstream
microprocessor must be present.
Here follows an Ethernet frame structure with EtherCAT:
Inside the Ethernet frames, data is transmitted among Master and Slaves using
PDO (Process Data Objects) protocol. Each PDO message has inside one or more
addresses for issuing data to the Slaves; data + address/es (and additional
elements such as a validation checksum) joined together forms an EtherCAT
telegram (Datagram).
MAN SFA_5000_10000_EC E 1.0.odt
6 - EtherCAT® interface
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