Sfc Program Creating Procedure - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
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.
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 individual processes, 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.
Stop
for
5 sec
Start
pushbutton
switch
35 SFC Program and Step Ladder
35.1 SFC Program
Start
Moving
LS1
forward
LS2 1st time
Moving
Moving
backward
forward
LS2
2nd time
Moving
backward
Initial
process
Start switch
Truck moves forward.
1st
process
MC1 is driven.
Limit switch for minor
LS1
forward movement
Truck moves backward.
2nd
process
MC2 is driven.
Limit switch for backward
LS2
movement
Stop
Stop timer
process
Timer
Truck moves forward.
3rd
process
MC1 is driven.
Limit switch for major
LS3
forward movement
4th Truck moves backward.
process
MC2 is driven.
Limit switch for backward
LS2
movement
31
32
LS3
33
34
35
36
37
38
A
B
757