I am trying to export data for a report via the Easy Chart “save” button. Here is the issue I am having. If the comms to the device goes offline I see the Easy Chart stop showing data as expected. When I go and look up the tag in the database I see a new entry for the data is NULL as expected. I believe the problem arises in the way the software interpolates the points between the loss of comms phase and the reconnection phase when data starts flowing back in. The Easy Chart shows what is expected which is no line while comms are lost but the export data makes the data appear to “Ramp” back up to the 1st data point after comms have been reestablished.
I understand how Ignition uses the set deadband in order to store less points in the DB and interpolates all the data in between the points it stores which is great. However in this case I feel that it needs to store a NULL point when comms are reestablished and then a point with the new 1st value coming in from the device. That way it would show that no values were coming into the device rather than showing what appears to be a ramp feature.
I have attached the graph that I can get from the exported data to show what I am saying. I turned of comms to the device for a few minutes and when I turned them back on this is how the data appears to look which is not correct. Is there a way to fix this so that the data would show a value of NULL or zero for the entire time comms are down then jump up to the new value when comms are reestablished?
Chart_Table.pdf (168 KB)