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11. PLC Help Function
11.3 PLC Switches
- 388 -
The following shows an example of operation of special relay SM from the user PLC.
(1) Two-point switch
(Example) When two opposite switches, chip conveyer manual and chip conveyer automatic,
are provided;
RST M2
RST M1
Always ON
MOV K4M200 R138
M10E
M10F
SM94
M20F
SM95
M20E
RST M2
M10E
M10F
RST M2
M10E
M10F
M2
RST M1
M10E
M10F
M1
RST M1
M10E
M10F
Chip conveyer manual
Switch 15 highlight signal
Chip conveyer automatic
Switch 16 highlight signal
Always ON
MOV R38 K4M100
R38 bitE
R38 bitF
M1
M2
SM94
SM95
1scanwidth
(a) (b) (c) (d) (e)
(g)
(f)
Switch 15on Switch 16 on Switch 15 on
(a)Whenswitch15(R38bitE)isonand
switch 16 (R38 bitF) is off, R138 bitE
and M1 turn on. [Initial state]
(b)Whenswitch16(R38bitF)turnson
while being in state (a), R138 bitE turns
off, SM94 turns on, and M1 turns off.
(c) Turning SM94 on reverses R38 bitE
(to off).
(d) When R38 bitE is off and R38 bitF is
on,SM94 turns off and R138 bitF and M2
turn on.
(e)Whenswitch15(R38bitE)turnson
while being in state (d), R138 bitF turns
off, SM95 turns on, and M2 turns off.
(f) Turning SM95 on reverses R38 bitF
(to off).
(g) When R38 bitF is off and R38 bitE is
on, SM95 turns off and R138 bitE and
M1 turn on again.
R138 bitE
R138 bitF