Rockwell Automation Allen-Bradley ArmorBlock 1732E-IB8M8SOER User Manual page 67

The Sequence of Events module still timestamps input transitions for any
events that occur on Enable Timestamp Capture-enabled inputs. The module
stores up to 256 events per input.
The module stores up to 256 events per input. Each input's buffer is
IMPORTANT
independent of the others.
You must manage the module buffer effectively to make sure that the
module timestamps all transitions on a specific input.
Consider the following example:
You are using Retrieve by Point to retrieve timestamp data from input 4,
and 10 of the first 34 input transitions that the Sequence of Events
module timestamps occur on input 4.
If Latch Timestamp is enabled for the module and you fail to clear any of
the timestamp data for input 4 before the input transitions again, the
Sequence of Events module will not timestamp the next transition for
input 4, even though there are 126 slots still available in the module's on-
board buffer.
Additional Module Settings Required with Retrieval by Point Method
By default, the Sequence of Events module operates as if the controller will use
Standard Retrieval to retrieve data. To use the Retrieval by Point method, you
must change the following two tags in the module's output word:
• O.RetrieveByPoint = 1 (default value is 0)
• O.PointtoRetrieve = input point for which you want the controller to
retrieve data – for example, if you want to retrieve the data for input 8,
you must change this tag to 8.
Retrieval Process Similar to Standard Retrieval
After you make the output tag changes listed above, the controller retrieves the
data for each transition on the specified input in the order in which the
transitions occur.
The only exception to the process is that in Retrieval by Point, the current event
is not necessarily the data in the first slot of the on-board buffer. Instead, the
current event is the first slot (up to 256 events per input) that contains data for
a transition timestamped at the specified input.
For example, if you are using Retrieval by Point to retrieve data for input 7 and
the first transition that occurs on input 7 is the 5th transition the module
timestamped, the current event is located in slot 5 of the module's on-board
buffer.
Change Between Retrieval Methods
When using the Sequence of Events module in FIFO mode, you may determine
that you need to change retrieval methods. You can change retrieval methods,
but keep the following in mind before doing so:
• The change will NOT take effect until all events are acknowledged/
cleared from the module's buffers.
• When you change retrieval methods dynamically, the ideal way is to reset
events in the module buffers (as described above) and immediately
Rockwell Automation Publication 1732E-UM003D-EN-E - November 2021
Chapter 10 Use the Sequence of Events Input and Scheduled Output Modules
67