Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 55)

Publication 1756-UM528A-EN-P - April 2004
Using the Sequence of Events Module Features 5-3
Module Features That
Can Be Configured Table 5.2 lists features on the Sequence of Events module that can
be configured.
Two Operational Modes
The Sequence of Events module can operate in either of the modes
described in Table 5.3:
Table 5.2
This feature: is described on:
Two Operational Modes 5-3
Enable CST Capture 5-5
Chatter Detection 5-8
Software Configurable Input Filters 5-10
Latch CST 5-7
Electronic Keying 5-13
Module Inhibiting 5-15
Table 5.3
Operational mode: Description:
CST Per Point Mode The module produces timestamps for up to 2 input
transitions per input, one for OFF to ON transitions
and another for ON to OFF transitions; these
timestamps can occur simultaneously. This is the
default setting when you add the module to an
RSLogix 5000 project.
First In First Out (FIFO) Mode The module timestamps an unlimited number of input
transitions, regardless of direction (i.e., either OFF to
ON or ON to OFF) or input (i.e., the same input can
transition many times and the module will timestamp
every transition) and stores them in an on-board
buffer.
The module is capable of storing the data for up to
160 input transitions in its on-board buffer at a single
time. However, if you retrieve data from the buffer
effectively (i.e., retrieve the data before the module
timestamps greater than 160 input transitions), the
module can timestamp an infinite number of input
transitions.
We recommend you use this mode if you want to
minimize propagation delay of new input data being
reported to the controller. For more information on
propagation delay, see page 2-4.