Rockwell Automation 1732E-OB8M8SR EtherNet/IP Dual Port 8-Point SOE Input and Scheduled Output Modules UM - Manual (Page 19)

Rockwell Automation Publication 1732E-UM003B-EN-E - March 2014 9
Module Overview and Features Chapter 2
All input point event times are recorded and returned in a single buffer. The
module returns two 64-bit timestamps for each input, thus allowing:
• ON and OFF events for each point to be displayed simultaneously in the
input data.
• ladder logic not being explicitly required to see events, although needed to
archive events.
• events to be kept in the controller memory during remote power loss thus
eliminating data loss.
All inputs on the module can be filtered for both ON to OFF and OFF to ON
transitions. The timestamp for a filtered input will be the time of the initial
transition to the new state and not the time that the filter validates the event as
real.
Selective Event Capturing allows particular events to be disabled per input and
per transition, ON to OFF or OFF to ON.
Event latching ensures that events are not overwritten. A single transition in each
direction is recorded per point. Any new event, which occurs after the point has
captured a timestamp, is dropped until the stored events have been
acknowledged.
If latching is not enabled in point mode, new events will overwrite old events
when they are received. In FIFO mode, up to 256 events per input will be
buffered before events are overwritten. Thus, if inputs are changing rapidly it may
be possible that events will be lost either in the module or the controller prior to
an event being operated on by ladder logic.
When events are lost, either old ones being overwritten or new ones being
ignored due to latching, an EventOverflow bit will be set for each point that loses
an event. The EventOverflow bit will clear when the blocking events for that
point are acknowledged.
Timestamping is a feature that registers a time reference to a change in input
data. For the 1732E-IB8M8SOER, the time mechanism used for timestamping is
(PTP) system time. The 1732E-IB8M8SOER module is a PTP slave-only device.
There must be another module on the network that functions as a master clock.
High Performance Sequence of Events Applications in the Logix
Architecture
Sequence of Events (SOE) applications span a wide range of industry
applications. Typically any event that needs to be compared against a second
event can be classified as SOE.
• Used on discrete machines to identify failure points
• Used in Power Substations or power plants to indicate first fault
conditions