Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 91
Fast Module Features Chapter 5
Figure 9 - Valid Transition with No Bounce
Figure 10 - Transition Valid with Bounce
Figure 11 - Invalid Transition
012345678
Input turns On, and a
timestamp is recorded.
Time in milliseconds
Input remains On for at least 2 ms. The transition is 
considered valid, and the timestamp is sent to the controller.
012345678
Time in milliseconds
Input turns On and remains On for at least 2 ms in the 
20 ms time period that is 10x the input filter time. 
The module sends the timestamp recorded at the 
original transition point (time 0) to the controller.
Input turns Off before 2 ms elapses.
Input turns On, and a
timestamp is recorded.
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Time in milliseconds
Input turns Off before 2 ms elapses.
The input never remains 
On for at least 2 ms.
After the 20 ms time period that is 10x the input filter 
time, the module drops the data recorded at the 
original transition. If an RPI occurs during this time, 
the module sends the controller its current valid input 
data. The data that is sent does not include data from 
the transition because the input transition has not 
cleared the filter and been recognized as a valid input.
Input turns On, and a
timestamp is recorded.
The next time the input turns On, the module 
records the transition as timestamp 21.6 once 
the input passes the filter time.
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