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1 Features and System Configuration
CJ-series EtherCAT Slave Units Operation Manual (W541)
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-1 In
trod
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to Et
herCA
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ypes of Ether
CA
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Communications
The following 2 types of communications are available with EtherCAT.
PDO communications are executed in each EtherCAT communications cycle to refresh data continu-
ously. SDO communications are executed between PDO communications.
PDO communications transfers process data cyclically and in realtime.
The EtherCAT master maps the logical process data space to the nodes to achieve cyclic communica-
tions between the EtherCAT master and slaves.
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Types of EtherCAT Communications
Process Data Communications (PDO Communications)
Ethernet
header
CRC
Ethernet data (1,498 bytes max.)
Data
Header
WKC
1st to nth EtherCAT datagrams
EtherCAT
header
1st EtherCAT
datagram
2nd EtherCAT
datagram
nth EtherCAT
datagram
. . . . .
EtherCAT frame
Ethernet frame
WKC: Working counter
Summary of Contents for CJ1W- ECT21
Page 1: ...Cat No W541 E1 02 OPERATION MANUAL SYSMAC CJ Series CJ1W ECT21 EtherCAT Slave Unit ...
Page 8: ...CONTENTS 6 CJ series EtherCAT Slave Units Operation Manual W541 ...
Page 30: ...Revision History 28 CJ series EtherCAT Slave Units Operation Manual W541 ...
Page 32: ...Sections in this Manual 30 CJ series EtherCAT Slave Units Operation Manual W541 ...
Page 148: ...Appendices A 34 CJ series EtherCAT Slave Units Operation Manual W541 ...
Page 149: ...I 1 I CJ series EtherCAT Slave Units Operation Manual W541 Index ...
Page 152: ...I 4 CJ series EtherCAT Slave Units Operation Manual W541 Index ...
Page 153: ......