773
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
3. Example of parallel branch
Do not use MPS, MRD, MPP, ANB and ORB instructions in a program with branches and recombination.
Even in a load driving circuit, MPS instructions cannot be used immediately after STL instructions.
In the same way as programs for general state relays, program the drive processing first, and then program
the transfer processing.
Continuously program all transfer processing.
4. Example of parallel recombination
Do not use MPS, MRD, MPP, ANB and ORB instructions in a program with branches and recombination.
Even in a load driving circuit, MPS instructions cannot be used immediately after STL instructions.
Pay attention to the programming order so that a branch line does not cross a recombination line.
Before recombination, first program the drive processing of state relays.
After that, program only the transfer processing to recombination state relays.
<List program>
STL
OUT
LD
SET
SET
SET
21
20
Y000
1
X000
TRAN
X000
Y001
STL
S20
SET
S21
S20
Y000
X000
S21
S31
S41
31
41
SET
S31
SET
S41
<Step ladder>
<SFC program>
Drive
processing
Transfer
processing
STL
OUT
STL
OUT
STL
OUT
STL
STL
STL
LD
AND
AND
SET
50
29
Y010
STL
S29
STL
S39
S29
Y010
S39
Y011
S49
Y012
S29
S39
S49
X010
X011
X012
S50
Y010
STL
S49
39
Y011
49
Y012
Y011
Y012
STL
S39
STL
S49
STL
S29
X010
SET
S50
9
X010
TRAN
X011 X012
X011 X012
<Step ladder>
<List program>
<SFC program>
Drive
processing
Transfer
processing