Chapter 7 Second Development PlatformVP3000
287
Instruction Function
PLF Differential output at falling edge
Operand
X0–X17 Y0–Y17 M0–M799 T0–159 C0–C79 D0–D399
－ － － －
Description
Differential output at falling edge instruction. When X0 goes from ONOFF (the falling-
edge is triggered), PLF instruction is executed, M0 sends pulses once and the pulse
length is one scanning time.
Example
Ladder diagram:
X0
M0
PLF
M0
Y0
SET
Sequence diagram:
Instruction code Operation
LD X0 Load X0 (the contact A)
PLF M0
Differential output at
falling edge of M0
LD M0 Load M0 (the contact A)
SET Y0
Maintain the action of
Y0 (ON)
Instruction Function
END Program end
Operand N/A
Description
END instruction has to be placed in the end of a ladder diagram or instruction program.
PLC scans from address 0 to END instruction, and then return to address 0 to restart the
scan.
Instruction Function
NOP No operation
Operand N/A
Description
NOP instruction does not perform any operations in the program; therefore, after the
execution of NOP, the existing logical operation result will be kept. If you want to delete a
certain instruction without altering the length of the program, you can use NOP
instruction.
Example
Ladder diagram:
Instruction code Operation
LD X0 Load X0 (the contact B)
NOP No operation
OUT Y1 Drive Coil Y1
To Next Page
Loading...
