ABB FECA-01 - Ethercat Services

88 Communication protocol
The EtherCAT frame structure is pictured in the following figure.
Each EtherCAT telegram consists of an EtherCAT header, the data
area and a working counter, which is incremented by all EtherCAT
nodes that are addressed by the telegram and have exchanged
associated data.
EtherCAT services
EtherCAT specifies services for reading and writing data from the
physical memory within the slaves. The adapter module supports
the following EtherCAT services:
• Auto increment physical read (APRD)
• Auto increment physical write (APWR)
• Auto increment physical read write (APRW)
• Configured address read (FPRD)
• Configured address write (FPWR)
• Configured address read write (FPRW)
• Broadcast read (BRD)
• Broadcast write (BWR)
• Logical read (LRD)
• Logical write (LWR
CRC
CRC
Destination
Ethernet
header
IP header
Length
Embedded directly in Ethernet
Frame with EtherType 0x88A4
Source
EtherType Header
…
UDP
header
Header
…
Res.
Type
1...n EtherCAT
telegrams
01112
15
48 bits 48 bits 16 bits 16 bits 32 bits
160 bits 64 bits
11 bits 1 bit
4 bit
Or: via UDP/IP
with UDP Port 0x88A4