Ladder Program - YASKAWA MP2200 User Manual

5.2.2 Ladder Program

( 1 ) Types of Drawings (DWG)
Ladder programs are managed in units of ladder drawings, which are identified by drawing numbers. These drawings
form the basis of user programs.
Ladder drawings include parent drawings, child drawings, grandchild drawings, and operation error processing draw-
ings. In addition to drawings, there are functions that can be freely accessed from each drawing.
• Parent Drawings
Parent drawings are automatically executed by the system program when the execution conditions, outlined in
the table below, are met.
• Child Drawings
Child drawings are accessed using a SEE command from a parent drawing.
• Grandchild Drawings
Grandchild drawings are accessed using a SEE command from a child drawing.
• Operation Error Processing Drawings
Operation error processing drawings are automatically executed by the system program when an operation error
occurs.
• Functions
Functions are accessed and executed from parent, child, and grandchild drawings using the FUNC command.
[ a ] Drawing Types and Order of Priority
Drawings are classified by their first letter (A, I, H, or L) based on the processing purpose. The following table outlines
the order of priority and execution conditions for these drawings.
Type of Parent
Drawing
DWG.A
Startup processing
(Drawing A)
DWG.I
Interrupt processing
(Drawing I)
DWG.H
High-speed scan pro-
(Drawing H)
cessing
DWG.L
Low-speed scan
(Drawing L)
Note: Lower values have higher order of priority.
The following table provides details of the number of drawings for each drawing.
Drawing
Parent Drawings
Operation Error
Processing Drawings
Child Drawings
Grandchild Drawings
Function Priority
Power ON
1
(Executed once only, when power turns ON)
External interrupt (executed by Optional Mod-
2
ule DI interrupt or counter match interrupt)
Periodical startup
3
(Executed each high-speed scan)
Periodical startup (Executed each low-speed
4
scan)
DWG.A DWG.I
1 (A) 1 (I)
1 (A00) 1 (I00)
Total: 62 max. Total: 62 max.
Execution Conditions
Number of Drawings
DWG.H
1 (H)
1 (H00)
Total: 198 max.
5.2 User Programs
5.2.2 Ladder Program
Max. No. of
Drawings
64
64
200
500
DWG.L
1 (L)
1 (L00)
Total: 498 max.
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