Trending directly on operator screen PG2
I'm trying to add trending of selected variables directly on the operator screen as a part of the GUI. the problem is configuring the template correctly as my trend lines do not appear.
I define the trend template, and define the tag to be trended in the "Trace01NormValue" property (see figure "trend_1"). Initially I tried to define the trend variable in the "Trace01CurrentValue" property, but I get a conflict with the assigned datatype. For the "Trace01CurrentValue" the datatype is 'HistoryReference' (InitOnly). This can be seen in figure "trend_4".
In short; when I define the trend tag using the "Trace01NormValue" property, nothing appear except the trend background. When using the "Trace01CurrentValue" property, I get a conflict error when trying to apply.
I have not tried using the XY graph or plot, and I don't belive using these is the only solution.
Can somebody help me explain what i do wrong here?
as far as I know you cannot refer to a log. Trace01CurrentValue has to be a property of an object, eg Value. Then, if Value is used in at least one Log Configuration, you can get History data in your trend. Verify the difference between Trace01UseBufferedData true and false.
I have tried what you suggest without success. The same error persist as the attached figure "trend_2" depict. From the error message I interpret that the expression for datatype 'HistoryReference' (InitOnly) for this item has something to do with it, but I don't understand what. On the other hand I may be far out on a limb here.
Any further idea, Stefan?