Historian tag chart - line w/ shape


first of all, happy and prosperous 2018 to all of you!

I’ve been struggling with displaying historian tag in a way our users want. Here’s our setup concerning this tag:

  • historian tag has scanclass
  • the tag can change its value not often than each 2-4 minutes
  • I’d like to depict it in easychart with line w/ shape

Problem is, that the phase, where the tag value is constant, is crowded with shapes (namely square), See attached picture, please. What I want to get is, one shape per change of the tag. How can this be achieved? I get lot of squares on the horizontal part even if displayed time range is in seconds.

Following the chart (please observe the horizontal parts of the khaki chart - crowded with squares):

You could try adjusting the Tag History Resolution property. I think by default its fixed and uses a value of 300. If you use Natural the number of points will depend on the scan class. I’ve found with shapes and lines it’s usually best to limit the number of points. Hope that helps.



thank you for your reply. Pardon my ignorance, but I cannot see where this setting can be adjusted. Tags themselves are instances of UDT (one UDT represents 1 machine type, there are many machines of this type - where I need to change this discussed behavior - in Ignition).

Thank you in advance for your help.

Best regards,