Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 82)

Publication 1756-UM528A-EN-P - April 2004
6-10 Using The Sequence of Events Module in CST Per Point Mode
Copying Relevant Input Data to a Separate Data Structure
When the Sequence of Events module sends input data to the
controller, the data is stored in the controller tags. We recommend
you use a COP or CPS instruction to programmatically copy new
timestamp data from the controller tags to a separate array in the
controller’s memory. Later, you can combine timestamp data from
multiple Sequence of Events modules and use a Sort routine to
determine the order of events, with relative time reference, that
occurred in a specific time period.
I.ReturningUCTTime Modulewide Indicates if timestamps are in UCT format rather than CST.
0 = CST format
1 = UCT format
For more information on UCT format, see Appendix B.
I.EventNumber.x Modulewide Running count of the timestamped transitions; this tag increments by one with each
new transition that the module timestamps. In CST Per Point mode, this tag has lesser
importance than in FIFO mode.
This value is cleared if the module is reset, as described on page 6-14.
I.Timestamp[16].OffOn[2] Per point Timestamp value (in CST or UCT format) with an input’s OFF to ON transition. This tag is
a 16 x 2 32-bit array. There is a 64-bit timestamp per point.
This value is cleared after the data has been acknowledged via the O.EventAck and
O.NewData tags. For more information on clearing timestamp data, see page 6-12.
I.Timestamp[16].OnOff[2] Per point Timestamp value (in CST or UCT format) with an input’s ON to OFF transition. This tag is
a 16 x 2 32-bit array. There is a 64-bit timestamp per point.
This value is cleared after the data has been acknowledged via the O.EventAck and
O.NewData tags. For more information on clearing timestamp data, see page 6-12.
(1) This tag is a 32-bit tag. The lower 16 bits represent the 16 inputs on the Sequence of Events module.
Table 6.3 Input Tags in CST Per Point Mode
Tag name: Set on a Per Point or
Modulewide basis: Description:
IMPORTANT
When you copy relevant timestamp data from the
controller tags to a separate data structure, make sure
you copy enough information for each timestamp
that you can differentiate between timestamps for
different inputs.