Hi all,
We have a pair of redundant standard gateways communicating with several edge gateways through a gateway network. Ignition version is 8.1.48 on all gateways (Windows..).
We are syncing all the history from the edges up to their respective datasource history provider on the main gateway. All the historical data goes into their respective partition tables etc. as it should. We can see historical data for months back in time in the databases.
In our application we have some power charts configured to display trends for historical data by using the tagpath of the objects that are defined on our different symbols.
So, on the source property of a pen on the power chart we have an expression binding like {instanceTagPath}+"/SomeHistoricallyEnabledTag".
At a first glance, this seems to be working good. We open a popup, pass the instance tag path and the power chart shows the trend for the default amount of time (1 week).
The case is that if we try to change the time range to say 2 months, the power chart only shows about 1 month of data before it cuts off the trend. Tags from other edge gateways may only show 2 weeks, and even just 5 days.
I am aware of the edge limitation of about a month of storage (35 days or 10 million points), so if I launch a session on the edge itself, I guess a month of historical data is expected.
But this is when launching a session on the main gateway.
The common thing, is that this method of using the tagpath does cut off the trend if the tag originate from a remote tag provider. When using the tagpath method on a tag originating from the main gateway tag provider, it works just fine.
And if we browse and add the tags manually from the tag browser in the power chart, all the history is displayed as expected with no cut off.
Example with the same tag history in both plots, but the tagpath method (upper plot) cutting of the trend about 1 month back in time:
Example of a tag from a different edge with same setup (tagpath method in the upper plot, and tag browse/historical path in the lower plot) and only 5 days of data back in time on the tagpath method:
As of Ignition 8.1.14 (according to the user manual), the power chart should support both methods, converting non-historical tag paths to a historical format:
If I instead use the tagpath that we are providing to the power chart, and create the historical format based on it, the trend shows historical data as it should. So we might just need to implement the tagpath conversion to historical format ourselves. But this should work straight forward by using tagpath as stated in the user manual?
Anyone having similar experience with this?
Seems to me being some kind of a bug related to remote tag providers, but might have overlooked something.
We are in contact with support, but they have not been able to find any errors in our setup yet. Hoping someone here might have dealt with similar challenge and want to enlighten us with their observations 
Thanks,
Andreas
