Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 97)

Publication 1756-UM528A-EN-P - April 2004
Using The Sequence of Events Module in FIFO Mode 7-11
Table 7.3 Input Tags in FIFO Mode
Tag name: Set on a Per Point or
Modulewide basis: Description:
I.Fault
Per point
(1) Indicates if a fault has occurred for the input.
0 = no fault
1 = fault – The fault can be chatter or communication fault as described below:
• Chatter - The Sequence of Events module can detect chatter on individual inputs
and will set the appropriate tag to 1 when chatter exists on an input. For
example, if the module has detected chatter on input 4, I.Fault.4 = 1.
• Communication fault - The controller sets this tag to 1 for all 32 bits if a
communication fault occurs on the module.
This tag clears when the fault that causes the condition no longer exists.
I.Data
Per point
(1) Status of the input point. This data is filtered if the Input Filter feature is used on the
module. Thus, an input change must pass through the filter before it is seen in this tag.
0 = input is OFF
1 = input is ON
For example, if input 3 is ON, I.Data.3 = 1.
I.NewData
Per point
(1) Flag indicating if new timestamp data was detected on the input.
0 = no new timestamp data on the input
1 = new timestamp data on the input (since last acknowledged)
Because input data for all inputs is sent immediately after each timestamped transition
and at each RPI, this tag is useful to quickly determine on which input the transition
occurred. For example, if the Sequence of Events module sends new input data to the
owner-controller and I.NewData.5 = 1, you know that at least one of the timestamps for
input 5 (i.e., I.Timestamp[5].OffOn or I.Timestamp[5].OnOff) has new data.
This tag only clears when the controller acknowledges the new data or all events on the
module are reset. For more information, see page 7-17.
I.EventOverflow
Per point
(1) Set for an input when the module either:
• Does not timestamp an input transition – The module has Latch CST enabled and
the module’s on-board buffer contains 160 timestamps. In this case, the module
does not have room in its on-board buffer to store the timestamp from any
additional events and does not timestamp new transitions.
or
• Overwrites previously-recorded timestamp data – The module has Latch CST
disabled and the on-board buffer contains 160 events. In this case, the module
continues to timestamp input events. When the module records new transitions,
it records the data in its buffer and overwrites the timestamp data from the
oldest transition of the 160.
This value is cleared if the module is reset or when an event is acknowledged.