6 - 6
(a) Condition
The constant scan time needs to satisfy the following relational expression.
If the sequence program scan time is longer than the constant scan setting time, the CPU module detects
"PRG. TIME OVER" (error code: 5010).
In this case, the constant scan setting will be ignored and the sequence program scan time will be applied.
If the sequence program scan time is longer than the WDT setting time, the CPU module detects "WDT
ERROR".
In this case, the program execution will be stopped.
(4) Waiting time from when END processing is executed until next scan starts
Sequence program processing is stopped during the waiting time from when END processing of a sequence
program is executed until next scan starts.
(a) When a low-speed execution type program is executed
Execution of the low-speed execution type program will be stopped when the time reaches the following point.
(Constant scan) - 0.5ms
(b) When an interrupt factor occurs during waiting time
Either of the following programs is executed.
• Interrupt program
• Fixed scan execution type program
(WDT setting time) > (Constant scan setting time) >
(Sequence program maximum scan time)
Figure 6.3 Operation when the scan time is longer than the constant scan setting time
0
12
3
412
3
4
00
1
END 0END
2
3
412
3
4
0END 0END
3.5ms 0.5ms
4ms 4ms
3.5ms 3.4ms 0.6ms
4ms5.3ms
5
ms
0.5ms
Scan where the constant scan setting is not applied
Constant scan setting (4ms)
Constant
scan
Sequence
program
To Next Page
Loading...
Need help?
General
