The other day I encountered an MS Excel report that was displaying some extremely wrong values for data that it was pulling from a GE Historian 3.1 server that was recording data from an iFix 4.5 system. What I mean is that these values should have been in the ballpark of 300-600 Amps and not 3-6 Amps. Well, I should say that these numbers were actually like 317.21234 Amps and 3 Amps. So, after staring at this system for a bit, in despair, I realized this was a scaling issue with some rounding involved. I changed the Engineering units on the Historian tags to match those on the iFix tags and the new data coming in from iFix was recorded correctly in Historian and displayed properly on the Excel report.
What I believe happened is that when the Historian server was originally set up, the tags were imported from the iFix Collector running on the iFix server. Of courese, this import of tags transferred the iFix Engineering Units over to the Historian box. Then, I think someone adjusted the iFix Engineering Units, but neglected to adjust the Historian Engineering Units. It is important to adjust both, so that the above problem does not happen.
What I want to do is create either an iFix pic, MS Excel spreadsheet, or stand-alone VB program that will adjust the various properties of iFix/Historian tags in both the iFix and Historian systems. This will be a fun Project!
