Echelon i.LON 100 e2 Internet Server - Manual (Page 83)

i. LON 100 Internet Server Programmer’s Reference 6-11
6.2.1.4 DataLoggerRead
Use the DataLoggerRead function to retrieve the entries in the log files generated by your
Data Loggers. You can specify which log entries the function will return by filling the
properties described in Table 16 into the parameter you supply to the function.
Table 16 DataLoggerRead Input Properties
Property Description
The index number of the Data Logger to return log entries for.
The name of the data point for which log entries are to be returned. If
you do not fill in this property, the function will return log entries for
all data points the Data Logger is monitoring.
Use this field to specify the maximum number of log entries the
function will return. If you do not fill in this property, the function will
return all log entries for the applicable data point (or data points) that
were logged during the interval defined by the and
properties.
NOTE: You should not attempt to read more than 150 log entries with
a single call to this function.
Use these fields to specify a time interval for the log entries to be
returned. You can specify a start and stop time, or just a stop time.
If you specify a start and stop time and the number of log entries
during this interval exceeds the maximum defined by the
property, the function will return the first group of log
entries recorded during the interval.
If you only specify a start time, the function will return entries from
the log starting at the start time until it reaches the end of the log file,
or until it has returned the maximum number of entries (as defined by
the property).
If you only specify a stop time and the number of log entries during this
interval exceeds the maximum defined by the property,
the function will return the group of entries from the stop time going
backwards in the log until the maximum number of log entries have
been returned. If the property was not defined, the
function will return all log entries in the log, going backward from the
stop time. This may be useful for applications that need to read the
newest information logged.
If you do not enter a start or stop time, the function will return all log
entries for the applicable data points, up to the maximum.
You must enter the and properties as
timestamps in local time, with appended time zone indicators to denote
the difference between local time and UTC. For more information on
this format, see Local Times and Coordinated Universal Time on page
6-12.