| Richard,
MIR is the MCC Management Information Repository, and it is used
to store all MCC data, including historical data, dictionary, and
other data used by MMs.
Historian FM (what used to be called Historical Data Recorder) is
the MM that records historical attribute data in the MIR. Historian
FM also provides services to purge historical data in the MIR.
MMs that store their own data in the MIR are responsible for
deleting/purging the data they no longer need.
Alex
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| Actually, there are two ways to use the MIR routines. The first way,
is as an historical data store. In which case you would pass in the
the "time" argument the timestamp for the data (for example on a
write_attr_data call). The second way is to use it for a
non-historical data store. In this case, you would just pass the value
MCC$K_NULL_PTR for the "time" argument, which the MIR routines
interprets as "no time". Since matching records on writes are
"updated", another call would simply replace the "current" record with
a new record. Non-historical data storage is only valid for private
usage (such as the way MCC Alarms uses it).
Alex is correct about using the MIR routines for storing Historical
data. You must maintain the information (i.e., do the purging)
yourself.
-Matt.
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