Publication 1763-RM001C-EN-P - October 2009
30
I/O Configuration
Rising Edge Behavior - Example 2
The previous examples demonstrate rising edge behavior. Falling edge
behavior operates exactly the same way with these exceptions:
•
The detection is on the “falling edge” of the external input.
•
The input image is normally “on” (1), and changes to “off” (0) for
one scan.
TIP
The “gray” area of the Latched Status waveform is the
input filter delay.
IMPORTANT
The input file value does not represent the external input
when the input is configured for latching behavior.
When configured for rising edge behavior, the input file
value is normally “off” (“on” for 1 scan when a rising
edge pulse is detected).
Scan Number (X)
Scan Number (X+1)
Scan Number (X+2)
External
Input
Latched
Status
Input File
Value
Input
Scan
Ladder
Scan
Output
Scan
Input
Scan
Ladder
Scan
Output
Scan
Input
Scan
Ladder
Scan
Output
Scan
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