> I recently transferred an application from labview 5.1 to 6, and was
> surprised to note that the redraw of my graph legend is taking now
> more than 5 seconds instead of a fraction!
> I update the 32 fields of the legend by accessing an attribute node
> (now converted in to a property node) in a for loop. It also seems
> that the time needed to update the legend is longer when the graph
> contains a lot of point. Is it normal? How can I improve that (without
> re-installing labview 5.1...)?
There are some differences between the two, and it is possible
for LV6 property nodes to be slower than LV5 attribute nodes,
but it is easy to remedy. If your VI does lots of UI work,
and it sounds like yours does, then one option is to set the
VI to run in the UI e
xecution system. The primary reason for
the slowdown is the switching back and forth between the diagram
threads for execution and the UI threads for updating the graph.
If the entire VI is run in the UI thread, then it will be more
efficient as the swaps do not need to happen.
A different sort of fix, and one that will make it even faster,
is to add two additional property nodes to Defer and reinstate
Panel Updates. You are probably updating the legend in a loop,
before the loop set the value of the property to TRUE and after
the loop and all other property intensive code set it to FALSE.
The property is reached by taking a VI property node, choosing
the Panel reference property, wiring that to a second property
node and choosing the Defer Panel Updates from the menu.
Greg McKaskle
