Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1981

Processing details
■Operation processing
When (s) turns off, (d) turns on only for one scan.
■Operation result
1.
Function block without EN/ENO
The operation processing is performed. The operation result is output from (d).
• Timing chart
ON ON
(s)
OFF OFF
ON
(d)
OFF
(1) (2)
(1) (d) turns on at the falling edge of (s).
(2) (d) turns off in the next scan.
2.
Function block with EN/ENO
The execution conditions and operation results will be as follows.
Execution condition
EN
TRUE (executed)
FALSE (not executed)
• Timing chart
ON
EN
OFF
ON
(s)
OFF OFF
ON
ENO
OFF
ON
(d)
OFF
(1)
(1) (d) turns on at the falling edge of (s) while EN is on.
(2) (d) turns off in the next scan.
(3) If EN is off, (d) holds the output value of the last scan.
Operation error
There is no operation error.
ON ON
OFF OFF
ON ON
Operation result
ENO
TRUE
FALSE
ON ON
ON ON
OFF
ON ON
ON
OFF OFF
(2) (3)
ON ON
OFF OFF
ON ON
OFF
(d)
Operation result output value
Previous output value
ON
ON ON
OFF
ON
35 EDGE DETECTION FUNCTION BLOCKS
OFF
ON
ON
ON
OFF
ON
ON
OFF
35.2 Detecting a Falling Edge
35
1979