Creating A Plc Ladder Program; Execution Order Of The Sample Program - Delta DVP-ES2 Operation Manual

Ladder Diagram
Structure
S

1.5.1 Creating a PLC Ladder Program

The editing of the program should start from the left side bus line to the right side bus line, and from
up to down. However, the right side bus line is omitted when editing in WPLSoft. A single row can
have maximum 11 contacts on it. If more than 11 contacts are connected, a continuous symbol "0"
will be generated automatically and the 12th contact will be placed at the start of next row. The
same input points can be used repeatedly. See the figure below:
X1 X2
X0
X12
X11
0
When evaluating the user program, PLC scan starts from left to right and proceeds to next row
down until the PLC reaches END instruction. Output coils and basic / application instructions
belong to the output process and are placed at the right of ladder diagram. The sample program
below explains the execution order of a ladder diagram. The numbers in the black circles indicate
the execution order.
X0 X1
M0
X3 M1

Execution order of the sample program:

1 LD X0
2 OR M0
3 AND X1
4 LD X3
AND M1
ORB
5 LD Y1
AND X4
6 LD T0
AND M3
ORB
7 ANB
8 OUT Y1
TMR T0 K10
Explanation
Multiple output branches
Output coil
Step ladder
Basic / Application
instruction
Inverse logic
X4 X5 X6 X7
X3
X13
Y1 X4
T0
M3
Instruction Available Devices
MPS
MRD None
MPP
OUT Y, M, S
STL S
Basic instructions and API
- instructions. Please refer to
chapter 3 Instruction Set
INV None
C1
X10 C0
0
Y1
Y1
TMR T0 K10
1 . PLC Conc e pts
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