Assigning I/O Refreshing To Tasks - Omron NJ-series User Manual

Precautions for Correct Use Precautions for Correct Use
• Set the System Service Monitoring Settings to the minimum values that are required to meet
the response performance of the system services so that sufficient time can be allocated to
the system services and task execution. The System Service Monitoring Settings are used to
monitor whether the specified system service execution time can be obtained. System ser-
vices will not necessarily be executed for the specified time.
• Design the tasks so that sufficient time can be allocated to execution of the system services.
Refer to 5-3 Task Design Methods and I/O Response Times for the setting procedures for
tasks.
• To increase the system service execution time, increase the task period or take other steps to
increase the unused time between task execution.
• If the time that is specified in the System Service Monitoring Settings cannot be allocated to
the system service execution time even if execution of tasks with an execution priority of 17 or
higher is interrupted, an Insufficient System Service Time Error occurs and user program exe-
cution stops.
• If sufficient system service execution time cannot be allocated and execution of tasks with an
execution priority of 17 or higher is interrupted, a Task Period Exceeded error will occur for the
tasks that are interrupted. Design the tasks so that the execution of tasks with an execution
priority of 17 or higher is completed within the task periods even if the execution time of the
system services satisfies the System Service Monitoring Settings.

5-2-10 Assigning I/O Refreshing to Tasks

I/O refreshing of the EtherCAT slaves and the CJ-series Units is assigned to the tasks. You can assign
them to the following tasks.
Classification
EtherCAT slaves Communications Coupler Unit for which there is a
CJ-series Units
Note The I/O refreshing for a slave or Unit can be assigned to only one task.
Precautions for Safe Use
If two different function modules are used together, such as when you use CJ-series Basic Units
and EtherCAT slaves, take suitable measures in the user program and external controls to
ensure that safety is maintained in the controlled system if one of the function modules stops.
The relevant outputs will behave according to the slave or Unit specifications if a partial fault level
error occurs in one of the function modules.
Refer to 12-1-3 Non-fatal error in CPU Unit for details on partial fault level Controller errors.
NJ-series CPU Unit Software User's Manual (W501)
I/O refresh target
NX Unit assigned to an axis on the Slave Terminal
Communications Coupler Unit for which there is not
a NX Unit assigned to an axis on the Slave Terminal
Slaves assigned to axes
Other slaves
Basic I/O Units
Special I/O Units
CPU Bus Units
5 Designing Tasks
Tasks to which assign-
ment is possible
Primary periodic task
Primary periodic task or
priority-16 periodic task
Primary periodic task
Primary periodic task and
priority-16 periodic task
Primary periodic task and
priority-16 periodic task
5
Assigned
unit
By Slave
Terminal
By slave
By Unit
5-31