Mitsubishi Q00JCPU User Manual page 428

6
FUNCTIONS
Basic
Note6.52
Note54
Basic
Note6.52
6
- 128 6.16 Watchdog Timer (WDT)
(c) Scan time when WDT instruction is used
The scan time value is not reset even if the watchdog timer is reset in the
sequence program.
The scan time value is measured to the END instruction.
Internal
processing time
END
WDT reset
(CPU module internal processing)
POINT
1. Scan time is the time from when the CPU module starts processing a
sequence program at Step 0 until it restarts processing another sequence
program with the same filename at Step 0.
The scan time is not consistent for each and changes depending on the
followings.
• Whether the commands used are executed or not executed.
• Whether to execute or not an interrupt program and a fixed scan
execution type program.
2. To execute at the same scan time at every scan, use the constant scan
function. (
The Basic model cannot execute fixed scan execution type programs.
Sequence program
Scan execution
Scan execution
0
type program B
type program A
Scan time
Watchdog timer measured time
Figure 6.84 Watchdog Timer Reset
Note6.52
Note54
Section 6.2)
Internal
processing time
Scan execution
END 0
type program A
Next scan time
WDT reset
(CPU module internal processing