Delta AS Series Programming Manual page 278

Instruction code
FB_PN
Device DX DY
S
Data type

S
Symbol
Explanation
1. When the value in the accumulative register switches from 1 to 0, the FB_PN instruction keeps the value 1 in the
accumulative register for a scan cycle. After the second scan cycle is finished, the value in the accumulative register
changes to 0.
2. The previous state of the contact is stored in the bit device S. Do not use S repeatedly in the program. Otherwise,
the wrong execution result appears.
3. Use FB_PN only in function blocks.
Example
Instruction
LD M0
AND M1
FB_PN D0.0
OUT Y0.0
Timing diagram
M0
M1
Y0 .0
Operand
S
X Y M
 
S ： For internal use
Operation
Contact A of M0 is loaded.
Contact A of M1 is connected in series.
The circuit is falling edge-triggered.
The coil Y0.0 is driven.
One scan cycle
One scan cycle
C ha pt er 5 Bas ic I ns t r uc t i ons
Triggering the circuit on the falling edge.
SM S T

Function
C HC D

5 - 2 1
5_