Display of Compressed Values in the Event Screen
The RDB compression provides the display of compressed values, which have been calculated from a compression calculation, in the WinCC OA Event Screen (see also Alert and event panel, basics).
Compressed values can be displayed only in the event screen in the closedmode, if RDB is used. The combination of compressed values and basis values of data point elements in the table of the event screen is supported.
The following example demonstrates how to display compresses values in the event screen. It is assumed that the data point, for which the calculation of compressed values takes place, already exist. In the following example the data point element Valve.Valve_R1.Valve_1 is used, which has already been created in the chapter Mass Configuration of multiple Data Point Elements. The data point element has the both compression calculations shown in the following figure. Their results will be shown in the event screen.
This is how to display compressed value in the event screen
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Click the Eventscreen button in the Diagnostics tab of the WinCC OA system management to open the event screen.
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Click the button to open the properties of the event screen.
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Select the Closed mode in the Timerange tab and optional define the start and the end of the time range.
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Open to the Filter tab.
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Click the button to open the DP selector.
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Select the _original config of the data point element Valve.Valve_R1.Valve_1 in the DPE tab of the DP selector, click OK to confirm and add it to the filter list.
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Re-open the DP selector. Select the compression calculation Valve.Valve_R1.Valve_1._1min_sum of in the Compression tab of the DP selector, click OK to confirm and add it to the filter list.
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Repeat step 7 for the compression calculation Valve.Valve_R1.Valve_1._1min_max.
In order to add all compression calculation of a certain data point to the filter list, wildcards can be used. Therefore click the "DP search" button. For further information see Properties of the alert table.
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Click OK in the properties of the event screen to apply the setting and start the display in the event screen by clicking .
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As well the compressed values as the original values of the data point element are now displayed in the event screen. For example:
In the data point element description of compressed values the compression step of the compression calculation is shown in brackets ("DP element/Description" column). Instead of the alert text ("Content" column) the compressed value is shown. If for the data point element a value, which could be compressed, has not been received until now, the value 0 is displayed in the event screen.
The return data point type of compressed values must be float in order to display AVG (average values) for int values correctly.