745
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
Transfer of state relay ON status by a same signal
In some cases, it is necessary to transfer the state relay ON status by the ON/OFF operation of one
pushbutton switch.
To achieve such a transfer, it is necessary to convert the transfer signal into pulses in programming.
The following two methods are available to convert the transfer condition into pulses:
1. Procedure using PLS instruction
Immediately after M0 turns ON and then S50 turns ON, the
transfer condition M1 (NC contact) is open. As a result, it
is not possible to transfer the ON status to S51 at the same
time when S50 turns ON.
When M0 turns ON again, the ON status is transferred to
S51.
2. Procedure using a pulse contact instruction
(M2800 to M3071)
By using an auxiliary relay M2800 to M3071 in a rising/
falling edge detection instruction (LDP, LDF, ANDP,
ANDF, ORP or ORF), the ON status can be efficiently
transferred by the same signal.
When M2800 or later is specified as a device in a rising/
falling edge detection instruction, only the first rising/falling
edge detection instruction after a coil instruction is
executed. Accordingly, when X001 is set to ON, only the
transfer condition in a state relay currently in the ON status
is ON during one operation cycle, and then the ON status
is transferred to the next state relay.
*1.
It is alright to program a device number used in LD, LDI, OR or ORI instructions after a corresponding
coil in the ladder block. However, if a same device number is programmed in LDP, LDF, ANDP,
ANDF, ORP or ORF instruction, the priority is given to such an instruction and the transfer condition is
not effective.
51
50
M0
M1 M0
1
2
3
TRAN
PLS
M1
TRAN
PLS
M2
M2 M0
TRAN
Pulse signal
51
50
X001
0
2
3
TRAN
Ladder block
SFC block
(Transfer input)
M2800
M2800
M2800
1
M2800
TRAN
M2800
TRAN
M2800
*1