120
12 SCAN MONITORING FUNCTION
12.1 Scan Time Monitoring Time Setting
12 SCAN MONITORING FUNCTION
This function detects CPU module hardware or program errors by monitoring the scan time. Using the watchdog timer, which
is an internal timer in the CPU module, the following scans are monitored.
• Initial scan (1st scan)
• 2nd scan and after
12.1 Scan Time Monitoring Time Setting
Sets the scan time monitoring time.
Navigation window [Parameter] [Module model name] [CPU Parameter] "RAS Setting" "Scan Time
Monitoring Time (WDT) Setting"
12.2 Resetting of the Watchdog Timer
Resets the watchdog timer when the END/FEND instruction is executed. When the CPU module operates normally and
executes the END/FEND instruction within the watchdog timer setting, the time of the watchdog timer will not time up. If the
END/FEND instruction cannot be executed within the watchdog timer setting due to increased program execution as a result
of hardware error or interrupt in the CPU module, the time of the watchdog timer will time up.
Item Description Setting range Default
Initial Scan Sets the scan-time monitoring time (WDT) for the initial scan (first scan). 10 to 2000ms (10ms units) 2000 ms
After 2nd Scan Sets the scan-time monitoring time (WDT) for the second and later scans. 10 to 2000ms (10ms units) ■FX5S CPU
module
500ms
■FX5U/FX5UC
CPU module
200 ms
To Next Page
Loading...
