Supporting Functions; Event Log; Event Enabling/Masking - Allen-Bradley Rockwell Automation 857 User Manual

Event Log

Supporting Functions

Event log is a buffer of event codes and time stamps including date
and time. For example each start-on, start-off, trip-on or trip-off of
any protection stage has a unique event number code. Such a code
and the corresponding time stamp is called an event. The event codes
are listed in a separate document Allen-Bradley_Events.pdf.
As an example of information included with a typical event an
overvoltage trip event of the first 59 stage U> is shown in the
following table.
Table 4.1 – Typical Overvoltage Trip Event
Event
Code: IE2 Channel 30, event 2
U> trip on Event text
2.7 x In Fault value
2007-01-31 Date
08:35:13.413 Time
Type: U12,23,31 Fault type
Events are the major data for a SCADA system. SCADA systems are
reading events using any of the available communication protocols.
Event log can also be scanned using the front panel or using
SetPointPS. With VAMSET the events can be stored to a file
especially in case the relay is not connected to any SCADA system.
Only the latest event can be read when using communication
protocols or SetPointPS. Every reading increments the internal read
pointer to the event buffer. (In case of communication error, the
latest event can be reread any number of times using another
parameter.) On the local panel scanning the event buffer back and
forth is possible.

Event Enabling/Masking

In case of an uninteresting event, it can be masked, which prevents
the particular event(s) to be written in the event buffer.
There is room for 200 latest events in the event buffer. The oldest
one will be overwritten, when a new event does occur. The shown
resolution of a time stamp is one millisecond, but the actual
resolution depends of the particular function creating the event. For
example most protection stages create events with 10 ms or 20 ms
resolution. The absolute accuracy of all time stamps depends on the
time synchronizing of the relay. See "System Clock and
Synchronization" for system clock synchronizing.
Description Local Panel
Yes
Yes
Yes
Yes
Yes
Yes
4
Chapter
Communication
Protocols
Yes
No
No
Yes
Yes
No
857-UM001A-EN-P – July 2009