Rockwell Automation Allen-Bradley ArmorBlock 1732E-IB8M8SOER User Manual page 53

decrementing the number of 1 ms intervals counted until it reaches zero.
At this point the module stops filtering the input and discards the
timestamp. During this continued scan period, one of the following
events occurs:
- At some point while still filtering the input, the input returns to the
transitioned state and remains there until the module counts the
number of 1 ms intervals equal to the filter setting. In this case, the
module sends data from the transition to the controller.
- The input does not remain in the transitioned state for a time period
equal to the filter setting and the 1 ms counter decrements to zero. In
this case, the module does not consider the original transition valid
and drops the timestamp.
The following example illustrates how the module's input filters operate.
In the example, a module:
• Is Timestamp Capture-enabled for all of its points
• Uses a 2 ms input filter setting for OFF to ON transitions
Three possible scenarios can result after an input transitioning from OFF to
ON in the given circumstances.
• Scenario #1 (no bounce) – The input turns ON and remains for the full
2 ms. In this case, the module considers the transition valid and sends
the data recorded at the transition to the controller.
Note the input is sampled as being on three different times: 0 ms, 1 ms
and 2 ms.
Figure 12 - Scenario #1
Input turns ON;
timestamp recorded
0
• Scenario #2 – The input turns ON but turns OFF before 2 ms (length of
the input filter setting) elapses. In this case, the module continues to
scan the input every millisecond. At some point, less than 2 ms later, the
input turns ON again and remains for 1 to 2 ms, the third ON sampled
1 ms interval (in this case at 6 ms). In this case, the module considers the
transition valid and sends the data timestamped at the original
transition to the controller.
Figure 13 - Scenario #2
Input turns OFF before 2 ms have elapsed.
Input turns ON;
timestamp recorded
0 1
Rockwell Automation Publication 1732E-UM003D-EN-E - November 2021
Chapter 8 Specific Features of the 1732E-IB8M8SOER Sequence of Events Input Module
Input remains ON for at least 2 ms; transition is considered valid and the
timestamp is sent to the controller
1 2 3 4 5 6
Time in milliseconds
2 3 4 5 6 7
Time in milliseconds
7 8
Input turns ON and remains ON for 1...2 ms.
The module sends the timestamp recorded at the
original transition point to the controller.
8
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