Sfc Program Creating Procedure - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
State relay number
Activated 31
2
Transfer
condition
32
3
Transfer condition
number
*1. Output coils can be used again in different state relays.

35.1.3 SFC program creating procedure

Create an SFC program using the following procedure:
1. Operation example
Motor
Forward:
MC1
Backward:
MC2
1) When the start pushbutton switch is pressed, the truck moves forward. When the limit switch LS1 turns
ON, the truck immediately starts to move backward.
(The limit switch LS1 is normally OFF, and turns ON when the truck reaches the forward limit. Other limit
switches function in the same way.)
2) When the truck moves backward and the limit switch LS2 turns ON, the truck stops for 5 seconds, and
then starts to move forward again. When the limit switch LS3 turns ON, the truck immediately starts to
move backward.
3) When LS2 turns ON after that, the truck driving motor stops.
4) When the start pushbutton switch is pressed again after a series of operations finish, the above operation
is repeated.
Internal circuit
When X001
turns ON
*1
Y030
SET Y31
X001
TRAN
*1
Y030
Y032
S32 is activated,
and S31 is
X002
TRAN automatically
reset.
Start
pushbutton
switch
31
X001
Activated
32
X002
Start
Moving
forward
LS2
1st time
Stop Moving
backward
for
5 sec
LS2
35 SFC Program and Step Ladder
35.1 SFC Program
Y030
Y31 programmed
SET Y31
in SET instruction
remains ON even
TRAN
if S31 turns OFF.
Y030
Y032
TRAN
LS1
Moving
LS3
forward
2nd time
Moving
backward
803
31
32
33
34
35
36
37
38
A
B