Graph property node error 1077

[waynep]

I have read the other questions about error 1077 on a XY Graph Property node (relating to setting the Active Plot). In my case, the problem is encountered only occasionally and is not repeatable. I have a sub-VI (attached LV 7.0) that creates a plot and then sets the line width of each plot using a Property Node. I have taken care to write to the Graph in the first sequence step and set the property node in the second sequence step.

I have another program that calls this sub-VI 3 times and makes 3 plots with 3 property nodes to set the line width which is run in a For-Loop. It would be nice if the output formatting of the sub-VI graph would be used in the calling VI, but it doesn't do so. This works and runs hundreds of times without a problem, but then every once in a while I get the "Error 1077 at Property Node (arg1)..." in the sub-VI. I have found that this always happens on the last plot on the Graph (yes, I use 0 for the first active plot). I stop when the error occurs and look at the graph properties and the plot I am setting as active does exist in the list (right-click Graph / properties -> Plots tab -> Plot drop down list). In addition, I see the plot on the graph, but just not set to the line width I am setting it to. A probe on the data that is being written to the Graph shows the correct number of plots. If I run the sub-VI again with the same input data, it always works the second time. The example I attached will work by itself every time (I set to default the data that gave me the last error).

Any suggestions -- this is an aggravating problem? The number of plots is typically different each time the sub-VI is called.

Thanks for any help.

[MeghanK]

It looks like there was a CAR filed on this specific error that you are receiving.  Please view the linked discussion forum for a workaround.  Let me know if this helps, thanks!

http://forums.ni.com/ni/board/message?board.id=170&message.id=207048&requireLogin=False

[waynep]

Thanks for looking at my problem (which has now become unbearable). The thread you mentioned states: "error seems to occur if you are actively manipulating this graph at the same time you try to write to the Active Tool property". I am not manipulating the graph at all, just graphing in step 1 and writing the line widths in step 2 (in a sequence statement). Unfortunately, I cannot even look at the above code since I have LV 7.0 and the code is in 8.2.

With probes, I have verified that the number of plots written to the graph is correct, and that LV is complaining about setting the active plot of an existing plot. If I click on "continue" when I get the error, the program continues and properly sets the line widths. I think the problem is that I have several graphs in the same VI. It looks like LV gets confused about the # of plots in the property node I am writing to compared to the other property nodes. I write sequentially to graph1, property node 1, graph2, property node 2, graph3, property node 3 (each with a different # of plots). The VI may crash when writing plot #20 in property node 2 when graph1 has < 20 plots. Again, this only happens occasionally.

Any other suggested work-arounds? I can stop setting the line widths, but then the graphs look terrible. I haven't worked with subpanels before -- is it possible to have 1 graph in a subVI be displayed differently in 3 subpanels of a top level VI?

[waynep]

OK, I just figured out what to do. I have to set the # of Legend Plots to be equal to the number of plots and set the Legend Visible to FALSE. Even though I never had the legend visible (I have typically > 20 plots), I still have to set the number of plots in order to set the line width of that plot. To me, this is a LV bug that should be fixed. Anyway, I am happy I have a painless work around (although it was painful trying to find it).

[Liquid_Crystal]

Don't forget to take into consideration the Default Values that are Initialived when the program first runs.