Operational Flow And Cycle Time - Omron NE1A-SCPU01 - 07-2009 Operation Manual

Operational Flow and Cycle Time

11-2 Operational Flow and Cycle Time
Cycle time
IMPORTANT For a Controller that supports EtherNet/IP, the maximum cycle time is 60 ms.
The NE1A-series Controller's operations are outlined here.
The NE1A-series Controller initializes itself internally when the power is
turned ON. Unless there are errors, the Controller then cyclically executes
system processing, DeviceNet, EtherNet/IP, and USB communications pro-
cessing, I/O refreshing, and the user program. When DeviceNet communica-
tions disable (Standalone) is set, DeviceNet processing is omitted from the
cyclic execution.
In Standalone Controller mode, the Controller cyclically executes all but the
DeviceNet processes. The cycle time depends on the scale of the user pro-
gram and the configuration of DeviceNet remote I/O communications.
Normal mode flow
Power ON
Initialize
System processing
DeviceNet/EtherNet/IP/
USB communications
processing
I/O refresh
User application
calculation
The cycle time is expressed by the following formula.
NE1A-series Controller cycle time = System processing time
+ DeviceNet, EtherNet/IP, or USB communications processing
time
+ I/O refresh time
+ User application execution time
The cycle time of the NE1A-series Controller is set in 1-ms increments
according to the configuration. The cycle time can be checked from
the Network Configurator, on the Mode/Cycle Time Tab Page of the
Edit Device Parameters Window.
If a cycle time of more than 60 ms is set, correct the connection settings and
user applications and change the system configuration so that the cycle time
will be less than 60 ms.
Section 11-2
Standalone Controller mode flow
Initialize
System processing
USB communications
processing
Cycle time
I/O refresh
User application
calculation
Power ON
219