777
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
34 SFC Program and Step Ladder
34.2 Step Ladder
31
FN
C
275-FN
C
279
Da
ta
Tr
ans
fe
r 3
32
FN
C
280
-F
N
C
28
9
H
igh Speed
Pr
oces
si
ng 2
33
FN
C
290-FN
C
299
Ext
ensi
on Fi
le
R
egi
st
er
34
SF
C
•S
T
L
Pr
o
g
ra
m
m
in
g
35
In
te
rru
p
t
Funct
ion
36
Sp
e
cia
l De
vic
e
37
E
rro
r C
o
d
e
A
V
e
rs
ion U
p
In
fo
rm
a
tio
n
B
Ex
ec
ut
ion Ti
m
e
s
C
Appl
ic
ab
le
In
st
ru
ct
ion Li
st
Examples of flows with selective branches and recombination
1. Example of selecting and carrying large and small balls
The figure below shows a mechanism which selects and carries large and small balls using conveyors.
The upper left position is regarded as the origin, and the mechanism performs in the order “moving down
→
suction
→
moving up
→
moving rightward
→
moving down
→
release
→
moving up
→
moving leftward.”
When the arm moves down and the electromagnet pushes a large ball, the lower limit switch LS2 turns OFF.
When the electromagnet pushes a small ball, LS2 turns ON.
+
M
+
Small
Large
X004
LS4
X005
LS5
X001
LS1 Left limit
X003
LS3 Upper
limit
Origin
indication
Y007
Moving
rightward:
Y003
Moving
leftward:
Y004
Moving up:
Y002
Moving down:
Y000
CY1
X002
LS2 Lower limit
When a large ball is pushed, the piston does
not reach the lower limit and X002 does not
turn ON.
Proximity
switch
PS0
X000
Electromagnet
Y001
X026
Start