Mitsubishi Electric MELSEC FX3U Programming Manual page 832

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Examples of flows having selective branches and recombination
1. Operation of selective branch
• When two or more flows are provided
and either one is selected and
executed, it is called a selective branch.
• In the example shown on the right,
X000, X010 and X020 should not turn
ON at the same time.
• For example, when X000 turns ON
while S20 is ON, the ON status is
transferred to S21; S20 turns OFF, and
S21 turns ON.
Accordingly, even if X010 or X020 turns
ON after that, S31 and S41 do not turn
ON.
• The recombination state relay S50 is
driven by either one among S22, S32
and S42.
2. Example of selecting and carrying large and small balls
The figure below shows a mechanism which selects and carries large and small balls using conveyors.
The upper left position is regarded as the origin, and the mechanism performs in the order "moving down →
suction → moving up → moving rightward → moving down → release → moving up → moving leftward".
When the arm moves down and the electromagnet pushes a large ball, the lower limit switch LS2 turns OFF.
When the electromagnet pushes a small ball, LS2 turns ON.
X026
Start
Moving
rightward:
M
Y003
Moving
leftward:
Y004
Moving up:
Y002
Moving down:
Y000
830
X001
LS1 Left limit switch
X003
Origin
LS3 Upper
indication
limit switch
Y007
+
CY1 When a large ball is pushed, the piston does
not reach the lower limit and X002 does not
turn ON.
X002
LS2 Lower limit switch
Electromagnet
Y001
20
X000
1
TRAN
21
2
22
X002
3
TRAN
50
10
X004
LS4
Proximity
switch
Small
PS0
X000
35 SFC Program and Step Ladder
35.1 SFC Program
X010
4
TRAN
31
5
32
X012
6
TRAN
X005
LS5
Large
X020
7
TRAN
41
8
42
X022
9
TRAN
+