183
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
7 Basic Instruction
7.11 PLS, PLF
1
In
troduct
io
n
2
Ov
e
rv
ie
w
3
In
st
ru
ct
ion
Li
st
4
D
evi
ce
s
in
De
ta
il
5
Speci
fied t
h
e
D
evi
ce &
C
onst
a
nt
6
Bef
o
re
Pr
ogr
a
m
m
ing
7
Bas
ic
In
st
ru
cti
o
n
8
FNC0
0
-FNC0
9
P
ro
g
ra
m F
lo
w
9
FNC1
0
-FNC1
9
M
ov
e
&
C
om
par
e
10
FNC
20-
FNC
2
9
Ar
ith.
&
Logi
c
O
per
at
io
n
7.11
PLS, PLF
Outline
When PLS instruction is executed, an applicable device is activated during only one operation cycle after a
drive input turns ON.
When PLF instruction is executed, an applicable device is activated during only one operation cycle after a
drive input turns OFF.
For example, when PLC mode is changed in the way "RUN
→
STOP
→
RUN" while a drive input remains
ON, "PLS M0" operates, but "PLS M600 (backed up by the battery)" does not operate (when the PLC mode
switches from STOP to RUN) because the status of M600 is latched even while the PLC is in the STOP
mode.
1. Instruction format
→
For the number of instruction steps, refer to Section 7.15.
2. Applicable devices
S
: Except special auxiliary relays (M)
Explanation of function and operation
1. PLS instruction (rising edge pulse)
In the figure above, M0 is ON during only one operation cycle when X000 changes from OFF to ON.
2. PLF instruction (falling/trailing edge pulse)
In the figure above, M1 is ON during only one operation cycle when X000 changes from ON to OFF.
Instruc-
tion
Bit Devices
Word Devices
Others
System User
Digit Specification
System User
Special
Unit
Index
Con-
stant
Real
Number
Charac-
ter String
Pointer
X Y M T C S D
.b KnX KnY KnM KnS
T
C
D
R U
\G
V
Z Modify K
H
E
"
"
P
PLS
3
S
3
PLF
3
S
3
PLS
Pulse
Basic Instruction
PLS
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic
Operation Condition
PLF
Pulse Falling
Basic Instruction
PLF
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic
Operation Condition
ON
Circuit program
List program
Timing chart
X000
M0
PLS
0000 LD X000
0001 PLS M 0
X000
M 0
PLS
instruction
ON during
one operation
cycle
ON
Circuit program
List program
Timing chart
X000
M1
PLF
0000 LD X000
0001 PLF M 1
X000
M 1
PLF
instruction
ON during
one operation
cycle