1 structure of the ethercat data telegram, Structure of the ethercat data telegram, 3communication with the controller – Lenze i700 User Manual
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3
Communication with the controller
3.6
Ethernet over EtherCAT (EoE)
34
Lenze · i700 servo inverter · Reference manual · DMS 1.5 EN · 03/2014 · TD05
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3.6.4.1
Structure of the EtherCAT data telegram
The GCI protocol is used for communication.
The EtherCAT data telegram is shown below. Here, the GCI header represents the part of the
program that is independent of the type of command transmitted.
[3-2]
Structure of the GCI header within the EtherCAT frame
EtherCAT
Header
IP Header
TCP/IP
Header
GCI Header
P0 ... P4
EtherCAT
Footer
GMQ
GMT
GSV
GTI
SIZE
SIZE
res
res
Field
Size
Description
GMT
1 byte
GCI message type
0x01 Reserved
GSV
1 byte
GCI service identification
0x82
0x83
GMQ
1 byte
GCI message qualifier
Bit 7
rsp (Request/Response)
0
Request
1
Response
Bit 6
a (Abort)
0
Data transfer OK
1
Abort of the data transfer
• The transfer is either aborted by the client or the server of a
parameter data telegram.
• A message is aborted without any confirmation. If the client waits
for its message to be confirmed, it will receive the abort notice
instead.
Bit 5 ... bit 0
res (reserved)
0b000000
Data contents = 0
GTI
1 byte
GCI transaction ID
0x00 Serial number (transaction identification)
• For each client a definite serial number (0 ... 255) is allocated.
• The serial number in the multitasking environment is used for
referencing to the calling tasks (reverse transaction).
...
0xFF
SIZE
2 bytes
Length of the user data
• The user data area or the data telegram contains the parameter data.
Assignment of user data areas P0 ... P4
0x14 20 bytes
... ...
0x114 276 bytes
res
2 bytes
Reserved
0x0000 Data contents = 0