Lenze I/O system 1000 System Manual - Manual (Page 480)

EtherCAT Kommunikation
About EtherCAT
EtherCAT frame
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480 EDSIO1000 EN 7.0
10 EtherCAT communication
10.1 About EtherCAT
EtherCAT (Ethernet for Controller and Automation Technology) is an Ethernet−based
fieldbus system which complies with the application profile for the field of industrial
real−time systems. In contrast to the classic Ethernet communication, the I/O data in full
duplex operation are exchanged with 100 MBit/s. By this, the telegrams are delayed in the
ms−range.
The EtherCAT protocol optimised for process data is transported directly in the Ethernet
telegram, which, in turn, can consist of several subtelegrams, each operating a memory
area of the process image.
As each EtherCAT gateway is provided with a clear address (MAC address), the data−related
order is irrespective of the physical order of the EtherCAT gateway in the network.
10.1.1 EtherCAT frame
EtherCAT frames have the following structure:
Ethernet header Ethernet data FCS
48 bits 48 bits 16 bits 11 bits 1 bit 4 bits 48 ... 1498
bytes
32 bits
Destination Source EtherType Header Datagrams
Length Reserved Type
Ethernet header
The Ethernet header contains the following information:
ƒ Target address of the EtherCAT frame (destination)
ƒ Source address of the EtherCAT frame (source)
ƒ Type of the EtherCAT frame (EtherType)
Ethernet data
The Ethernet data contain the following information:
ƒ Length of the datagrams within the EtherCAT frame (length)
ƒ One reserved bit
ƒ Type of the datagrams within the Ether−CAT frame (type)
ƒ Datagrams
FCS
ƒ Checksum of the EtherCAT frame