Omron NX-ECC201 User Manual page 219

Free-Run Mode Operation
Free-run slave #1 in the figure labeled Example of I/O Refreshing Mode Operation on page 10-5 oper-
ates in Free-Run Mode.
This slave performs I/O processing based on its own unique timing ((C) and (D) in the figure), indepen-
dent of Sync0.
Example of I/O Refreshing Mode Operation
An example of operation in each I/O refreshing mode is provided in the following figure.
PLC
Function
Module
EtherCAT
Master Function
Module
EtherCAT
communications
path
Synced
slave #1
Synced
slave #2
Free-run
slave #1
NX-series EtherCAT Coupler Unit User's Manual (W519)
Primary periodic task Primary periodic task
Primary period Primary period
(example: 500 μs) (example: 500 μs)
Process data communications
Process data communica-
cycle (example: 500 μs)
tions cycle (example: 500 μs)
EtherCAT transmission
EtherCAT transmission
time
time
Period of Sync0
(example: 500 μs)
Sync0 Sync0
Output delay and
DA conversion time
Input delay and
AD conversion time
Processing for free-run slave #1
Primary periodic task
Primary period
(example: 500 μs)
Process data communica-
tions cycle (example: 500 μs)
EtherCAT transmission
time
Period of Sync0 Period of Sync0
(example: 500 μs) (example: 500 μs)
Sync0
(B)
(A)
Processing for free-run slave #1
(D)
(C)
10 I/O Refreshing
10 - 5
10