Yaskawa YASNAC PC NC PLC Programming Manual - Manual (Page 85)

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YASNAC PCNC PLC Programming Manual Chapter 6: PLC Instructions
(a) Function
The instruction detects the falling edge of a signal.
(b) Example
(c) Control conditions
• Working area address (APSH#XXXX)
Designate an address that is not used by other instructions. One byte is necessary
for one SUBP 004.
• Contact to be detected (ACT) and output of signal fall detection (R1)
ACT = 0: Falling edge of a signal is not detected; R1 = 0
ACT = 1: R1 value changes “0”
Å “1” Å “0” at the detection of the falling edge.
• Even if “ACT = 0” when the power is turned ON, it is not regarded as the falling edge.
2
2
• •
ACT
R1
“1”
“1”
“0”
“0”