Scada Display
The scada display in Delft-FEWS is used for displaying and monitoring data. The scada display shows one or more configurable schematic views that represent data values in some way. For example, to show the most recent data value of a given time series, it is possible to show just the numerical value, or to show a rectangle that varies in height depending on the data value, or to show a polygon that changes in colour when the data value crosses a certain threshold, etc. How data is represented and which data is shown can be configured in the scada display configuration file. The scada display is dynamically updated whenever new data becomes available in the system or whenever data is changed (e.g. in the time series editor). The scada display is comparable to the main map display, only the scada display does not and cannot refer to any geographical coordinate system.
Please note that the scada display in Delft-FEWS is only used for displaying data, it does not implement all features that could be expected from a SCADA (Supervisory Control And Data Acquisition) system.
The scada display shows one or more scada panels, which can be selected in turn from the list on the left hand side. It is also possible to have multiple scada displays, each one with different panels. In that case there would be one configuration file for each different scada display, each one with a different filename. The filename of each scada display should be registered in the DisplayInstanceDescriptors configuration file. When available on the file system, the name of the xml file for configuring a scada display is for example "ScadaTwentekanalen.xml". This scada display would be registered in the DisplayInstanceDescriptors configuration file with the following xml code:
<displayInstanceDescriptor id="ScadaTwentekanalen">
<description>Scada Display Twentekanalen</description>
<displayId>ScadaDisplay</displayId>
</displayInstanceDescriptor>
Scada Display Configuration
ScadaDisplay configuration root elements
displayName
TODO
dateFormat
TODO
numberFormat
TODO
variable
TODO
scadaPanel
TODO
Tips And Tricks
Resizing behaviour of an svg document within the scada display
In an svg file in the root element use the following attributes to control its resizing behaviour: width, height, viewBox, preserveAspectRatio.
1. If only width and height present, then the svg document gets an absolute size, appears in the top-left corner of the display and is never resized (not even when the display window is resized). This means it can be cut-off when the display window is too small.
2. If only viewBox and preserveAspectRatio are present, then the viewBox determines the rectangular region of the svg document that is drawn in the display window (the coordinates for the viewBox edges are the same as the coordinate system used within the svg file, usually the coordinates are in pixels). The preserveAspectRatio determines how the drawn region is sized and aligned within the display window. In this case the svg document is automatically resized when the display window is resized.
Examples:
resizing attributes in the svg root element |
effect |
viewBox="0 0 400 400" preserveAspectRatio="xMidYMid meet" |
The svg document is scaled to fit the display window and the aspect ratio is preserved. |
viewBox="0 0 400 400" preserveAspectRatio="none" |
The svg document is scaled and stretched to fill the window (aspect ratio is not preserved). |
width="1200" height="700" |
Only the region with coordinates 0 <= x <= 1200 and 0 <= y <= 700 pixels is shown. The svg document is not resized when the display window is resized. |
