Table of Contents
Advertisement
6
FUNCTIONS
(a) Setting time condition
Constant
scan
Sequence
program
(4) Waiting time from when END processing is executed until next scan
starts
Sequence program processing is stopped during the waiting time from when the END
processing of a sequence program is executed until the next scan starts.
(5) Constant scan accuracy
Refer to CHAPTER 10 for the constant scan accuracy.
As the constant scan time, set a value that satisfies the following relational
expression.
(WDT Set Time) > (Constant Scan Set Time)
> (Sequence Program maximum Scan Time)
If the sequence program scan time is longer than the constant scan setting time,
the CPU module detects "PROGRAM SCAN TIME OVER" (error code: 5010).
In this case, the constant scan setting is ignored and the sequence program is
executed based on its scan time.
Constant scan setting
0
1
2
3
4
0
END
0
3.5ms
4ms
Scan where the constant scan is not normal
Diagram 6.17 Operation when the Scan Time is longer than the Constant Scan setting time
If the sequence program scan time is longer than the WDT setting time, the CPU
module detects a WDT error.
In this case, the program execution is stopped.
1
2
3
4
5
1
END 0
0.5ms
3.5ms
5.3ms
4ms
6.9 Constant scan
2
3
4
1
2
3
4
ms
END
0
END
0
0.5ms
3.4ms
0.6ms
4ms
6
1
2
3
4
5
6
7
8
- 41
Advertisement
Table of Contents
