YASKAWA MP3000 Series Setup Manual page 137

4.1 User Program Types and Execution Timing
4.1.1 Ladder Programs
 Hierarchical Configuration
There are four types of ladder drawings: parent drawings, child drawings, grandchild drawings,
and operation error drawings.
• Parent Drawings
These drawings are automatically executed by the system program when the execution con-
ditions are met.
• Child Drawings
These drawings are executed when they are called from a parent drawing with a SEE instruc-
tion.
• Grandchild Drawings
These drawings are executed when they are called from a child drawing with a SEE instruc-
tion.
• Operation Error Drawings
These drawings are automatically executed by the system program when an operation error
occurs.
A parent drawing cannot call a child drawing from a different type of drawing. Similarly, a child
drawing cannot call a grandchild drawing from a different type of drawing. A parent drawing
cannot call a grandchild drawing directly. The parent drawing first must call the child drawing,
and then the child drawing must call the grandchild drawing. This is called the hierarchical con-
figuration of drawings.
The following figure shows the parent-child-grandchild structure in which a program is created.
4-4
Parent Child
Drawing Drawings
DWG. DWG. 01
DWG. nn
Note 1: = A, I, H, or L
DWG notation:
Note 2: The following notation is used for operation error drawings.
Grandchild
Drawings
DWG. 01.01
DWG. 01.02
DWG. 01.03
DWG. .
Grandchild drawing number
Child drawing number
Parent drawing type (A, I, H, or L)
DWG. 00
Fixed value (00)
Parent drawing type (A, I, H, or L) of the
drawing where the error occurs
User Functions
FUNC-001
FUNC-006
FUNC-032
FUNC-064