Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 105)

Publication 1756-UM528A-EN-P - April 2004
Using The Sequence of Events Module in FIFO Mode 7-19
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 10, you must change this tag to 10.
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 steps to retrieve the data are
the same as those described on page 7-13.
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 of the
on-board buffer. Instead, the current event is the first slot (out of
the full 160) 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, as shown in Figure 7.6.
Figure 7.6
0 1 1 0 0 1 0
1 1 0 0 1 1 0
0 1 0 0 0 1 0
1 1 0 0 1 1 0
1 0 1 0 0 1 0
1 1 0 0 1 1 0
1 0 1 0 0 1 1
0 0 0 0 1 1 0
1 1 0 0 1 0 1
1 0 0 1 1 1 0
1 1 1 0 0 1 1
1
2
3
4
5
6
7
8
9
159
160
4
2
8
11
7
1
2
9
10
12
5
0
1
1
0
0
0
1
1
0
0
1
43813
Current event – The module produces
the data in this slot because the
controller is using the Retrieve by
Point method to retrieve data.
In this example:
• O.RetrieveByPoint = 1
• O.PointtoRetrieve = 7