Mitsubishi Electronics FX3G User Manual

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 Series
Programming Manual - Basic & Applied Instruction Edition
35 SFC Program and Step Ladder
35.1 SFC Program
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.
<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.
M
Large backward
rotation
Origin
Small forward
rotation
Large forward
rotation
Small backward
rotation
Y023
Backward
rotation
Y021
Forward
rotation
X010
X011
X
013
X
012
X000
Start
M8000
Ladder
block
521
6
1
0
X000
M8047
RUN monitor
M8002
M8040
Initial pulse
M8040
X000
Start
All outputs disable
522
2
523
3
524
RET
END
SFC
block
M8002
S6
SET
Y020
M8034
M8046
Initial pulse
STL
state
ON
4
6
Start
X011
Small forward
rotation
Y023
X010
Small backward
rotation
Y021
X013
Large forward
rotation
Y023
X012
Large backward
rotation
Y021
TRAN
Y020
Origin
indication
TRAN
Y021
Forward
rotation
TRAN
Y023
Backward
rotation
TRAN
Y021
TRAN
Y023
Enable STL
monitoring
STL
transfer
disable
Initial state relay
Forward
rotation
Backward
rotation