Mitsubishi Electric MELSEC iQ-R Series - Page 1981

35 EDGE DETECTION FUNCTION BLOCKS
35.2 Detecting a Falling Edge
1979
35
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
2. Function block with EN/ENO
The execution conditions and operation results will be as follows.
• Timing chart
Operation error
There is no operation error.
(1) (d) turns on at the falling edge of (s).
(2) (d) turns off in the next scan.
Execution condition Operation result
EN ENO (d)
TRUE (executed) TRUE Operation result output value
FALSE (not executed) FALSE Previous output value
(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.
OFF OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
(s)
OFF
ON ON ON ON
OFF
ON ON
(d)
(2)
(1)
OFF
ON ON ON ON ON
EN
OFF OFF
ON
OFF
ON
OFF
ON
OFF
ONON ON
(s)
OFF
ON ON ON ON ON
ENO
OFF OFF
ON
OFF
ON
OFF
ON
(d)
(2)
(1)
(3)