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The Basic Instruction Set
3.4.10
Generating pulses
Instruction
PLS
PLF
*
PLC and PLF instructions can be used to set outputs (Y) and relays (M).
These instructions effectively convert a static signal into a brief pulse, the duration of which
depends on the length of the program cycle. If you use PLS instead of an OUT instruction the
signal state of the specified device will only be set to "1" for a single program cycle, specifically
during the cycle in which the signal state of the device before the PLS instruction in the circuit
switches from "0" to "1" (rising edge pulse).
The PLF instruction responds to a falling edge pulse and sets the specified device to "1" for a
single program cycle, during the cycle in which the signal state of the device before the PLF
instruction in the circuit switches from "1" to "0" (falling edge pulse).
To enter a PLS or PLF instruction in Ladder Diagram format click in the GX Works2 toolbar on
the tool icon shown above or press F8 . Then enter the instruction and the corresponding
device to be set in the dialog, e.g. PLS Y2.
Ladder Diagram
X000
0
2
X001
4
6
X0
X1
M0
M1
Y0
3 – 18
Function
Pulse, sets an device* for the duration of
a single program cycle on the rising edge
of the switching pulse of the input condi-
tion / device
Pulse Falling, sets a device* for the dura-
tion of a single program cycle on the fal-
ling edge of the switching pulse of the
input condition / device
PLS
M0
SET Y000
PLF
M1
RST Y000
An Introduction to Programming
Symbol
PLS
PLF
Instruction List
0
M0
1
2
3
4
5
M1
6
7
t
GX Works2 FX
F8
F8
LD
X000
PLS
M0
LD
M0
SET
Y000
LD
X001
PLF
M1
LD
M1
RST
Y000
The rising edge of the device X0
signal triggers the function.
In the case of device X1 the falling
edge of the signal is the trigger.
Relays M0 and M1 are only
switched on for the duration of a
single program cycle.
MITSUBISHI ELECTRIC
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