Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 13)

Publication 1756-UM528A-EN-P - April 2004
What is the ControlLogix Sequence of Events Module? 1-3
Two Modes of Operation
The Sequence of Events module can operate in either of the modes
described in Table 1.2:
You set the module’s operational mode when you choose a
communication format during initial module configuration.
Depending on operational mode, RSLogix 5000 creates different tags
for the Sequence of Events when it is added to a project.
For more information on each mode, see Chapter 6, Using The
Sequence of Events Module in CST Per Point Mode and Chapter 7,
Using The Sequence of Events Module in FIFO Mode.
What Else Does the
Sequence of Event
Module Do? The Sequence of Events module offers additional features that are
common to ControlLogix digital input modules, such as:
• Full software configuration via RSLogix 5000
• Removal and insertion under power
• Full Class I Division Compliance
• Agency Certifications (e.g. UL and CSA)
To see a full description of all the features available on your Sequence
of Events module, see Chapter 5, Using the Sequence of Events
Module Features.
Table 1.2
Operational mode: Description:
CST Per Point Mode The module timestamps up to 2 input transitions per input, one for OFF to ON transitions and another
for ON to OFF transitions.
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 buffers at a
single time. However, if you retrieve data from the buffers effectively, the module will never miss an
input transition, regardless of how many occur.