HF scientific Online Data Acquisition System - Manual (Page 29)

Ref 22838 (8/02)
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4.4 Database/Spreadsheet
In addition to the Citadel historical database it is also possible to log data
separately in a .csv format file (also called spreadsheet logging), which can be
opened directly using any spreadsheet program, such as Excel. The user has the
option of enabling/disabling this logging function as well as a choice of
where the data will be logged. The user can also specify the logging interval.
4.4.1 CSV File Logging
To use the facility of data logging, complete the following information inside
CSV File Logging.
Logging Enable: This check box is used to enable or disable the spreadsheet
logging.
Logging Interval: Interval of time at which Lookout saves the specified field as a
new row in the spreadsheet file. Please note that unlike the Citadel database where
the data is saved as a continuous trace, the spreadsheet data is a snapshot of the
data at the specified time intervals. The value needs to be entered in the format
HH:MM.
Log to Full-Path Name / Log to Monthly Subdirectory in Lookout: It is
possible to save the spreadsheet file either in the default Lookout directory or
using a fully specified path name. The major difference is that if the data is saved
in the Lookout directory, Lookout automatically creates a directory tree, which
makes it easy for retrieving and maintaining the data. For example Lookout would
automatically create a folder under the Lookout directory for the year 2002. In the
2002 folder it would create a folder for the current month. The spreadsheet file
would then be located in the month folder (d:\Program Files\National
Instruments\Lookout\2002\nov\turbidity.csv). At the start of a new month or year.
Lookout would create the appropriate folder/s. If the full path name option is
selected, the user needs to enter the desired path name where the file is to be
saved. In this case Lookout will NOT create the year/month folders automatically.
In order to address this problem, the process has been configured to automatically
concatenate a unique number at the end of the file name for each month. For
example if the file is to be saved under d:\HFScientificFiles\Turbidity, Lookout
will add a unique number to the end of the file name, which will make the file
name look something like Turbidity_36812.csv. If the full path name option is
selected the user needs to click on the Update File Name Now pushbutton for the
settings to take effect. The spreadsheet object has been configured to log only the
turbidity values for each device.
It must be noted that if the spreadsheet file is opened while Lookout is running,
Lookout cannot write new data to the file. Lookout will automatically create a
memory buffer where it will store this data until the .csv file is available again.