<4. Control Application Creation>
The above description shows that if the “The task aborts when the execution time...”
checkbox is ticked, control computation of the FCN-500 or FCN-RTU will stop even
if only one watchdog error is generated.
To prevent this, untick the “The task aborts when the execution time...” checkbox.
● Watchdog Time Setting
On the other hand, monitoring task execution time using watchdog time provides
important diagnostic information about the current state of the system.
Therefore, set the watchdog time described in Section 4.1.2, “Control Task Setup” to
the same value as the scan cycle to enable monitoring of the execution time of a
control task.
In this way, a watchdog error will be generated and recorded in the system log file
whenever a control task fails to complete execution within the specified duration.
Moreover, as described in Section 2.2.3, “Checking FCN-500, FCN-RTU
Performance,” control execution time increases as CPU load increases.
In cases where an increased CPU load for whatever reason is expected to affect the
entire system, set the watchdog time to a value between 80% and 90% of the scan
cycle.
With this setting, a watchdog error will be generated whenever the CPU load (%)
exceeds 80% to 90%, thus providing an effective means for monitoring the CPU
load.
Do not tick the “The task aborts when the execution time...” checkbox when using a
redundant CPU.
Watchdog time modifications cannot be applied through an online download. To
apply a watchdog time modification, stop the FCN-500 or FCN-RTU and perform an
offline download.
To Next Page
Loading...
Need help?
General
