Mitsubishi Electric MELSEC FX3U Programming Manual page 829

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
3. Example of cam shaft turning control
The limit switches X013 and X011 are provided in
two positions, large forward rotation angle and small
forward rotation angle.
The limit switches X012 and X010 are provided in
two positions, large backward rotation angle and
small backward rotation angle.
When the start button is pressed, the cam shaft
performs the operation "small forward rotation →
small backward rotation → large forward rotation →
large backward rotation", and then stops.
The limit switches X010 to X013 are normally OFF.
When the cam shaft reaches a specified angle, a
corresponding limit switch turns ON.
• When M8047 turns ON, the operation state
monitoring becomes valid. If either one among
S0 to S899 and S1000 to S4095 is ON, M8046
turns ON after the END instruction is executed.
• This SFC program adopts latched (battery
backed) type state relays so that the operation is
restarted from this process when the start button
is pressed even after the power is interrupted in
the middle of operation.
However, all outputs except Y020 are disabled
until the start button is pressed.
Ladder
block
Initial pulse
Initial pulse
<M8034: All outputs disable>
When M8034 is set to ON, all outputs to the outside turn OFF even though the PLC is executing each
program in RUN mode.
M8000
M8047
RUN monitor
Enable STL
monitoring
M8002 X000
M8040
Start
M8040
Y020
M8034
All outputs disable
M8002 M8046
SET S6
STL
state Initial state relay
ON
X000
Start
Small backward
rotation
X010
Large backward
rotation
Origin
Y023
Backward
rotation
SFC
6
block
0
STL
transfer
521
disable
1
522
2
523
3
524
4
6
RET
35 SFC Program and Step Ladder
35.1 SFC Program
Small forward
rotation
X011
Large forward
rotation
Y021
Forward
rotation
M
Origin
Y020
indication
X000
TRAN
Start
Y023
Forward
Y021
rotation
X011
TRAN
Small forward
rotation
Y021
Backward
Y023
rotation
X010
TRAN
Small backward
rotation
Y023
Forward
Y021
rotation
X013
TRAN
Large forward
rotation
Y021
Backward
Y023
rotation
X012
TRAN
Large backward
rotation
END
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