169
FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
6 What to Understand before Programming
6.2 Cautions on Creation of Fundamental Programs
1
Introduction
2
Overview
3
Instruction
List
4
Devices
in Detail
5
Specified the
Device &
Constant
6
Before
Programming
7
Basic
Instruction
8
FNC00-FNC09
Program Flow
9
FNC10-FNC19
Move & Compare
10
FNC20-FNC29
Arith. & Logic
Operation
6.2 Cautions on Creation of Fundamental Programs
This section explains cautions on programming.
6.2.1 Programming procedure and execution order
1. Contact configuration and steps
Even for a sequence circuit offering the same operation, the program can be simplified and the number of steps can
be saved depending on the contact configuration method.
1) It is recommended to write a circuit with many serial contacts in an upper position.
2) It is recommended to write a circuit with many parallel contacts in a left position.
2. Program execution and programming order
A sequence program is executed "from top to bottom" and "from left to right".
Code the sequence instruction list according to this rule.
(1)LD
(2)LD (3)AND
(5)OUT
(4)ORB
(1)LD
(3)OR
(2)AND
(4)OUT
ORB instruction is not necessary
(1)LD
(3)OR
(5)OUT
(4)ANB
(2)LD (1)LD
(2)OR
(3)AND
(4)OUT
ANB instruction is not necessary
(3)
(1)
(2)
(4)
(7)
(5)
(6)
(8)
(9) (10)
(11)
Executed