I have an Ignition server that has multiple projects. The projects all share the same realtime tag provider. However, there are multiple historical providers.
One of the projects is used to trend utility usage over time and has been collecting data since 2017. There is now a need to pull some of that data into the main plant project. The screen that I wrote uses the system.tag.queryTagHistory function to get the meter usage and then runs it through a python script to get that data in the format that I need for displaying it. This script runs great in the original project, but when I run it in the main project I get all None values from the queryTagHistory function.
I assume this is because the two projects use different datasources. When running this script through the original project, it finds the tag history info in the project’s datasource and gets the history. However, when running this script in the main project, it is looking at the main project’s datasource and sees no reference to the tag history so it just returns none.
Am I correct in this assumption? If so, how can I get this to work? The Ignition server is version 7.7