Scan Execution Type Program - Mitsubishi Q00JCPU User Manual

3
SEQUENCE PROGRAM CONFIGURATION AND
EXECUTION CONDITIONS
(2) Initial execution type program processing
3
3.3 Settings for Creation and Execution of Multiple Sequence Programs
- 27
3.3.1 Initial execution type program
(a) Execution sequence
When the execution of all the initial execution type program is completed, an END
processing is performed and a scan execution type program is executed at the
next scan.
Power supply OFF
STOP RUN
Initial execution
type program A
Initial execution
type program B
Initial execution
type program n
END processing
Scan execution type
program
Diagram 3.21 Execution sequence of initial execution type program
(b) Initial scan time
The initial scan time is the execution time of an initial execution type program.
When multiple initial execution type programs are executed, the initial scan time is
the time taken until the execution of all initial execution type programs is
completed.
1) Initial scan time storage location
The CPU module measures the initial scan time and stores it into the special
registers (SD522, SD523).
The initial scan time can be checked by monitoring SD522 and SD523.
SD522
Example: When SD522 is 3 and SD523 is 400, the scan time is 3.4ms.
2) Accuracy and measurement of initial scan time
The accuracy of the initial scan time stored into the special registers is
0.1ms.
The measurement of the initial scan time is continued even if the watchdog
timer reset instruction (WDT) is executed in a sequence program.
ON/
1 scan
SD523
Stores initial scan time of 1ms or less (unit s).
Stores initial scan time in 1ms units.
Diagram 3.22 Initial scan time storage location
When there are multiple initial
execution type programs, they
are executed in ascending
order of program setting.