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Chapter 10
Use the Sequence of Events Input and Scheduled Output Modules
70
Figure 18 - Ladder Logic Example
Acknowledge Timestamp Latching Timestamp Data
In most cases, Timestamp Latching is enabled. This means that once the
module timestamps an input transition, the module will not timestamp
another transition in the same direction on the same input until you
acknowledge the data from the first timestamped transition; when you
acknowledge data, you clear it from the module.
To clear data from the module, you must acknowledge them via the module
output tags. You can clear data in the following ways:
•
Clear latched timestamp data for specific inputs – As data is
acknowledged, it is cleared from the module, and the module will once
again timestamp the first new transition for the input in the cleared
direction(s).
To clear timestamp data for specific inputs, you must complete the
following steps:
a. Write to the EventAck output tag (O.EventAck). This tag determines
which edge you will clear (acknowledge).
• 0 = clear only the falling edge timestamp (I.Timestamp[x].OnOff)
• 1 = clear only the rising edge timestamp (I.Timestamp[x].OffOn)
• 2 = clear both the falling and rising edge timestamps
b. Change the NewDataAck output tag (O.NewDataAck.x) to a rising edge
(set the tag =1). This tag determines which inputs will be cleared
(acknowledged). There are 8 bits (x = 0...7) that can be transitioned;
each corresponding to an input. More than one bit can be transitioned
at the same time.
• If the bit = 0, change the bit to 1.
• If the bit = 1, change the bit to 0, wait for at least one RPI, and change
the bit to 1.
The corresponding I.EventOverflow and I.NewData tags are also cleared.
•
Clear all latched data for the module – This transition erases all
timestamp data from the module, clearing data from all inputs
Rockwell Automation Publication 1732E-UM003D-EN-E - November 2021
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