graph auto-scroll?

[david_jenkinson]

Hi,

I'm acquiring several hours worth of data during a test.  I am displaying the data on a graph control.  The graph x scale is set up to only show the previous 30 minutes worth of data.  I am periodically saving a snapshot of the graph for logging purposes during the test using the WFGraph.ExportImage method, but my problem is I always see the first 30 minutes.  I want the graph to auto-scroll to the right as I'm acquiring data, but I cannot seem to find a property or method to cause this behavior.  Is there a way to do this that I am not seeing?

Thanks

David J.

[elset191]

Sounds like you ought to switch to a chart, rather than a graph.

[david_jenkinson]

I don't think this would be trivial, as I have several places where I am querying and/or setting properties and methods of the graph, one of which is annotations.  Do charts allow annotations?

[Ipshita_C]

Hi David,

Please look at this knowledgebase article--it will answer several of your questions. In addition, using a chart is definitely a better idea. Hope this helps!

Ipshita C.

[david_jenkinson]

Hi Ipshita,

I am now currently automatically adding annotations to a graph, making heavy use of it for  post-processing of the data, which your article refers to.  I therefore would not want to switch to a chart, because charts do not support annotations.  

So do  you (or anybody) know of a way to get auto-scroll to function in a graph?

Thanks

David J.

Message Edited by david_jenkinson on 10-02-2009 11:37 AM

[elset191]

I don't know about auto-scrolling, but you can manually scroll using the XScale.Range property node.

[Ipshita_C]

Hi David,

You can add an X-scroll bar to a chart or graph using the properties. By suto-scroll if you mean auto-scroll the way it is enable for things like Listbox indicators, there is no feature for that available in either a waveform graph or chart. 

Ipshita C.

[BryanL]

Hi David,

You may consider setting the graph xscale dynamically if you prefer using graph than chart with the property node.

Best,

Bryan

[Cory_K]

You could use property nodes.

If you have a certain range in mind, for example 200 seconds.

Set x.max to current time

Set x.min to (x.max - 200)

That should 'autoscroll'