Process Data Communications Refresh Timing - Omron NX102 series User Manual

6 Process Data Communications and SDO Communications
6-1-2

Process Data Communications Refresh Timing

The process data communications cycle is the same as the task period of the primary periodic task or
the priority-5 periodic task for sequence control. It is also the same as the motion control period.
The control periods between each function module and between the function module and the slave are
shown as follows.
NJ/NX-series CPU Unit
PLC Function Module
Execution of user
program
Instruction
Motion
control
Axes
instruction
variables
Sequence control period
(Task period of primary periodic
task or priority-5 or priority-16
periodic task)
Task period of primary periodic task or priority-5 periodic task = Motion control period = Process data
communications cycle
Precautions for Correct Use Precautions for Correct Use
• You can use the priority-5 periodic task only with the NX701 CPU Units.
• With an NX701 CPU Unit, you can perform process data communications separately in each
task period of the primary periodic task and the priority-5 periodic task. If these two process
data communications cycles must be distinguished, the cycle for the primary periodic task is
called process data communications cycle 1 and the cycle for the priority-5 periodic task is
called process data communications cycle 2.
• With an NX701 CPU Unit, you can execute motion control in the primary periodic task and in
the priority-5 periodic task. If these two motion controls must be distinguished, the one exe-
cuted by the primary periodic task is called motion control 1 and the other executed by the pri-
ority-5 periodic task is called motion control 2.
• The NX102 and NX1P2 CPU Units and NJ-series CPU Units perform process data communi-
cations only in the primary periodic task.
6-4
Device
variables
Motion
Control
Function
Module
Axes
variables
Motion control period
(Task period of primary periodic
task or priority-5 periodic task)
EtherCAT communications
EtherCAT
Master
Function
Module
Process data communications cycle
(EtherCAT data transmission cycle)
This is the same as the task period of
primary periodic task or priority-5
periodic task.
NJ/NX-series CPU Unit Built-in EtherCAT Port User's Manual (W505)
Slave
Processing in slave
Data refresh cycle in slave
(depends on the slave)