Echelon i.LON SmartServer 2.0 - Manual (Page 66)

i.LON SmartServer 2.0 Programmer’s Reference 5-1
5 Data Loggers
You can use Data Loggers to monitor activity on your network. Each Data Logger will record updates
to a group of user-specified data points into a log file. The information recorded for each update
includes the value and status that the data point was updated to.
Each SmartServer supports up to ten Data Loggers. The log files for each Data Logger are stored in
the location specified by the Data Logger’s property.
You can create two kinds of Data Loggers: historical Data Loggers, and circular Data Loggers. A
historical Data Logger stops recording data point updates when its log file becomes full. A circular
Data Logger removes the records for older updates when its log file is full, and new updates occur.
The Data Logger can save either type of log file in an ASCII-text (.csv file extension) or binary (.dat
file extension) format. You can optionally store the ASCII-text files in compressed format to save
flash memory on the SmartServer.
You can specify the minimum amount of time that must elapse, and the minimum change in value
required, between log entries for each data point your Data Logger is monitoring. When an update to a
data point is logged, a subsequent update for that data point will not be logged until the minimum time
period specified for the data point has elapsed, and the minimum value change specified for the data
point has been met. If an input data points is updated more than once before the minimum time period
has elapsed after a log entry has been recorded, the older values will be discarded. Only the most
recent update will be recorded by the Data Logger when the minimum time period elapses. This
allows you to throttle the data entry into a log.
You can also define a threshold level for each Data Logger. The threshold level represents a
percentage. When the Data Logger’s log file consumes this percentage of the memory space allocated
to it, the Data Logger will enunciate that it is time to upload the log, and clear out some of the data.
The Data Logger makes this enunciation by updating the Data Logger’s alarm data point (called
nvoDlLevAlarm[x], where x represents the index number assigned to the Data Logger) to the status
AL_ALM_CONDITION. This feature may be useful when working with historical Data Loggers,
which are disabled when they become full. You could create an Alarm Notifier to trigger an alarm
notification when a log becomes full. For more information on Alarm Notifiers, see Chapter 7 of this
document.
You can access the data in a log file by manually opening the log file, or by using the Read function.
You can clear data from a log using the Clear function, or by sending an update to the data point
nviDlClear[x], where x represents the index number of the Data Logger to be affected. This is
described in more detail later in the chapter.
5.1 Overview of the Data Logger XML File
The #8000010128000000[4].UFPTdataLogger.xml file stores the configurations of each Data Logger
that you have added to the SmartServer. Each Data Logger is signified by an element in the
XML file. The configuration properties contained in each element define the configuration of
a Data Logger, and are described later in this chapter.
You can create new Data Loggers using the Set function, or by manually editing the
#8000010128000000[4].UFPTdataLogger.xml file. You can create up to 10 Data Loggers per
SmartServer. You can add more than 10 Data Loggers if you load the dynamic v40 XIF on your
SmartServer and you operate your SmartServer in Standalone mode. Note that using the v40 XIF with
the SmartServer operating in LNS mode (LNS Auto or LNS Manual) is not supported.
The following represents a sample #8000010128000000[4].UFPTdataLogger.xml file for a
SmartServer with two Data Loggers defined on it:
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
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