735
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
34 SFC Program and Step Ladder
34.1 SFC Program
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
2. Creating a process drawing
Create the process drawing shown on the right using
the following procedure:
1) Divide the operation described in the above
example into each process, and express each
process in a rectangle in the order of operation
from top to bottom.
2) Connect each process with vertical lines, and
write the condition for each proceeding process.
When performing repeated operations, indicate
with an arrow the process the truck will return to
after a series of operations finish.
3) Write the operation performed in each process on
the right side of each rectangle indicating a
process.
Initial
process
1st
process
2nd
process
Stop
process
3rd
process
4th
process
W
hen t
he s
tar
t s
w
it
c
h
i
s
pr
es
s
e
d
agai
n,
t
he t
ruc
k
per
fo
rm
s
t
h
e
s
a
me oper
at
ions
r
epeat
e
d
ly
.
LS2
LS1
LS2
LS3
Truck moves forward.
MC1 is driven.
Truck moves backward.
MC2 is driven.
Stop timer
Truck moves forward.
MC1 is driven.
Truck moves backward.
MC2 is driven.
Limit switch for minor
forward movement
Start switch
Limit switch for backward
movement
Timer
Limit switch for major
forward movement
Limit switch for backward
movement
