Detecting A Falling Edge - Mitsubishi Electric MELSEC iQ-R Series Programming Manual

18.2

Detecting a Falling Edge

F_TRIG
These function blocks detect a signal falling edge, and outputs the pulse signal.
Structured text
Instance name(CLK:=s,Q:=d);
Setting data
■Description, type, data type
Argument
s (CLK)
d (Q)
Processing details
■Operation processing
When (s) turns off, (d) turns on only for one scan.
■Operation result
The operation processing is performed. The operation result is output from (d).
• Timing chart
ON
(s)
OFF
ON
(d)
OFF
(1)
(1) (d) turns on at the falling edge of (s).
(2) (d) turns off in the next scan.
Operation error
There is no operation error.
18 EDGE DETECTION FUNCTION BLOCKS
196
18.2 Detecting a Falling Edge
Description
Falling edge detection input
Output
ON ON
OFF OFF
ON
(2)
ON ON
OFF OFF
ON ON
Type
Input variable
Output variable
ON
OFF OFF
ON ON
OFF
Data type
BOOL
BOOL