4.1 User Program Types and Execution Timing
4.1.1 Ladder Programs
4-5
4
Creating User Programs
The breakdown of the number of ladder drawings in each category is given in the following
table.
Controlling the Execution of Drawings
Drawings are executed based on their priorities, as shown in the following figure.
*1.
DWG.A drawings are executed immediately after the power supply is turned ON.
*2.
When an interrupt signal is input, execution of the DWG.I drawing is given priority even if execution of a DWG.H
or DWG.L drawing is currently in progress.
Note: The parent drawing of each drawing is automatically called and executed by the system.
Drawings
Number of Drawings
DWG.A
DWG.I
DWG.H
DWG.L
Parent Drawings
1
1
1
1
Operation Error
Drawings
1
1
1
1
Child Drawings
Total of 62 max.
Total of 62 max. Total of 998 max.
Total of 1,998 max.
Grandchild Draw-
ings
There are separate functions that can be called from the drawings as required. Functions are
executed when they are called from a parent, child, or grandchild drawing with the FUNC
instruction. You can create up to 2,000 functions.
Information
Power ON
DWG.A
(Startup Drawings)
Interrupt signal
DWG.I
(interrupt drawing)
Execution is continued
from the point before
the interrupt.
Every low-speed scan
Batch output
Batch input
DWG.L (low-speed scan
process drawing)
Every high-speed scan
Batch output
Batch input
DWG.H (high-speed
scan process drawing)
*1
*2