Yaskawa MP900 Series Ladder Programming Manual - Manual (Page 46)

4.2 Ladder Drawings
4.2.2 Controlling the Execution of Drawings
4-5
Programming
4
4.2.2 Controlling the Execution of Drawings
( 1 ) Controlling the Execution of Drawings
Drawings are executed based on their priorities, as shown in the following figure.
ΠThe parent drawing of each drawing is automatically called and executed by the system.
( 2 ) Scheduling the Execution of Scan Process Drawings
All scan process drawings are not executed at the same time. The following figure shows how execution time is allo-
cated to them based on their priority levels.
∗ This time is used to execute internal system processing, such as self-diagnosis.
The low-speed scan is executed during the time that is not used by the high-speed scans. Set the time of the high-speed
scan to approximately twice the total execution time of the high-speed drawings (DWG.H).
Power ON
DWG.A
Startup drawing
DWG.H
High-speed scan
process drawings DWG.L
Low-speed scan
process drawings
Every high-speed scan
Batch outputs Batch outputs
Batch inputs Batch inputs
Every low-speed scan Operation error Interrupt signal
DWG.X00
Operation error drawing
X: A, H, or L
Execution is continued from
the point before the error.
DWG.I
Interrupt process drawing
Execution is continued
from the point before
the interrupt.
Background*
DWG.L
DWG.H
High-speed scan High-speed scan
Low-speed scan
High-speed scan High-speed scan
: Execution in progress