Real-time Graphing and Processing
If the active document is a data table that is
linked to a file or a data sequence that contains
at least one data table that is linked to a file, it is possible to set up DataScene to
automatically reload data from the linked files. To do this, select the Refresh
Linked Data tool on the ToolBox to open
the Refresh Linked Data dialog box
with which automatic reloading from the linked files can be set up. Depending on
the type of the active document, DataScene
supports two data refreshing methods: periodic refreshing if the active
document is a data sequence, or real-time refreshing if the active
document is a data table. In
the former method, DataScene reloads data from the linked files periodically
according to a specific time interval. In the latter method, DataScene
monitors the status of the linked file, once the file is modified by another
program DataScene immediately reloads data from it.
If the active data table is
linked to a file and there is one or more series
that use the linked data table as their data source, DataScene
will automatically refresh these dependent series after reloading from the linked file. Graphing of real-time data can be achieved this way.
If any
of these series is the source series of a series
function, the destination series of the series function will be recalculated each time the data table is refreshed. This feature allows the
user to process real-time data using any supported series function (e.g. FFT
filter, Moving Average, Differentiation,
etc).
Note that in the case where a data sequence is the active document, the
current data table of the data sequence must be linked to a file in order to see
any change of the dependent graphs. This is because dependent series of a data
sequence always use the data of the current data table of the data sequence. If the current table of the data sequence is not linked to a file, its data will
not change and neither will its dependent series.
It is important to note that if the program that updates the linked file does not close the file
promptly after updating it,
DataScene will fail to reload from it because of the file protection of the
operating system. If the user needs to code
his/her own file updating program, he/she should flush the file stream and close the file
promptly after updating it.
See Also
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