TN Hist271 Resolving the NULL value problem after upgrading the Wonderware Historian
Description
This article from InSource shows how to resolve NULL value issues after you've upgraded from a lower version of the Wonderware Historian and you are no longer able to see previously stored data in the old history blocks and instead receive NULL values. This is caused by the fact that the older Wonderware Historian used another storage method and and the AIHistory table needs to updated. Re
- Author: Rufus Handsome
- Published: 04/18/2017
- Applies to: Wonderware Historian 2014 and 2014R2
Details
To resolve the NULL value issues, follow the below steps.
Step 1 - Backup the runtime database using the MS SQL Server Management Studio
Step 2 - Disable & Shutdown Historian using the SMC
Step 3 - Run the SQL script below against the Runtime database using MS SQL Server Management Studio
'*********** BEGIN SQL SCRIPT ***************'
Use Runtime
Go
Update Runtime..Tag
Set AIHistory = 1
Where TagType != 7
And TagName not like ‘Sys%’
'*********** END SQL SCRIPT **************'
Step 4 - Re-Enable and Restart Historian using the SMC
Step 5 - Check to see if you have data using the Historian Client Trend or Query tool.