Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 80)

Publication 1756-UM528A-EN-P - April 2004
6-8 Using The Sequence of Events Module in CST Per Point Mode
Managing the Data in CST
Per Point Mode In CST Per Point Mode, the Sequence of Events module sends all of its
input data to the controller immediately after an input transition has
been timestamped and at each RPI. You must manage the data coming
from the Sequence of Events module.
The following occurs in the process of the managing data coming
from the Sequence of Events module in CST Per Point mode:
1. The Sequence of Events module sends data to the controller.
2. The controller copies the relevant portions of the input data
to a separate array.
3. At the user’s discretion, the controller clears latched
timestamp data from the Sequence of Events module via the
O.EventAck and O.NewData tags, preparing the module to
timestamp the next transition.
This process is described in the rest of this section.
Module Sends Data to the Controller
Figure 6.2 shows an example of the Sequence of Events module
sending data to the controller. In the example, the following occurs:
1. Input 1 transitions from OFF to ON. (The input has Enable CST
Capture enabled.)
2. The Sequence of Events module timestamps the transition.
3. The module sends its input data, including the transition
timestamp from input 1, to the controller.
Figure 6.2
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 1 0 1 1 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
I.Fault
I.EventOverlow
I.ReturningUCTTime
I.EventNumber
I.Timestamp[16].OffOn[2]
I.Timestamp[16].OnOff[2]
I.Data
I.NewData
42793
1. Input 2 transitions
from OFF to ON.
2. Module timestamps
the transition.
3. Module sends input
data to the controller.
Sequence of Events module ControlLogix controller