Problem with chart tag history binding

version 7.5.6

Not sure why but I cant seem to get it to show “on change”. My device only updates once per hour at best, but the chart is showing about 10 or 20 entries per hour. Ive pretty much went thru every option but it cant produce the actual value at the proper time that it changed. any ideas? here is a screen shot of the chart and also a screen shot of the trend for the same point and you can see that it only changes about once per hour.




The tag history binding option has the ability to only show data “On Change.” So how is your tag history binding setup?

here is a screenshot of the chart settings.


I started looking at some of my other gateways with the same window.

the second is almost correct, but it seems to have 2 entries. its setup for closest value and on change. version 7.5.5 (b1255)

the first is how it was in 7.2.11-beta1 (b209), which seems like the correct way to show the data, imho. the setup back thendidnt have as many options, but on change and average are selected on the tag history binding.




It was determined what was going on here in a tech support call but I just wanted to post what we had discovered. If this is indeed the same case then what was going on was that after the upgrade from 7.2 to 7.5 there was a change in the way the analog history mode would log data when the deadband was set to 0.0. It was logging data every execution of the historical scan class regardless of the value changing or not. Since all those entries in were in the database then all that data was being returned with the on change filter.