Sfc (Melsap3) Features - Mitsubishi MELSEC-Q Series Programming Manual

1 GENERAL DESCRIPTION

1.2 SFC (MELSAP3) Features

(1) Easy to design and maintain systems
It is possible to correspond the controls of the entire facility, mechanical devices of each
station, and all machines to the blocks and steps of the SFC program on a one-to-one basis.
Because of this capability, systems can be designed and maintained with ease even by those
with relatively little knowledge of sequence programs. Moreover, programs designed by other
programmers using this format are much easier to decode than sequence programs.
Step transition
control unit for
overall process
Step transition control
unit for overall process
(block 0)
Transfer machine START
(initial step)
Station 1 START
(block 1 START)
Station 2 START
(block 2 START)
Station 3 START
(block 3 START)
END
(END step)
(2) Requires no complex interlock circuitry
Interlock circuits are used only in the operation output program for each step. Because no
interlocks are required between steps in the SFC program, it is not necessary to consider
interlocks with regard to the entire system.
(Headstock RETRACT
endpoint)
LS0
1 - 4
Station 1
control unit
Overall system
(SFC program)
Station 1
control unit
(block 1)
START
(initial step)
Pallet clamp
(step 1)
Drilling
(step 2)
Pallet unclamp
(step 3)
(END step)
SOL1
MT1-F
MT1-B
Headstock
rotation
MT2-R
(Machining
(Machining
START) END)
LS1 LS2
Station 2
control unit
Transfer machine
Station 2
control unit
(block 2)
START
(initial step)
Pallet clamp
(step 1)
Tapping
(step 2)
Pallet unclamp
(step 3)
(END step)
Clamp
SOL2
LS-U
Clamp UP endpoint
Clamp DOWN endpoint
LS-D
(Carriage ADVANCE
endpoint) (Carriage RETRACT endpoint)
LS-F
Station 3
control unit
Station 3
control unit
(block 3)
START
(initial step)
Pallet clamp
(step 1)
Workpiece unloading
(step 2)
Pallet unclamp
(step 3)
(END step)
MTO-F
MTO-B
Carriage
LS10
LS-R
1 - 4