I have a rather peculiar issue with my Citect Historian 2016 running on Windows Server 2012 R2. I've set up my historian to connect to redundant IO servers running Citect 2015(7.5). Also on the historian machine i am running software to generate reports. This software uses RSLinx Classic OEM to connect directly to my PLC. What i've noticed is that when RSLinx is running and properly connected to the PLC the connection test to my primary data source will fail but the secondary is successful. If i stop the RSLinx service and retest the connection it is successful to both data sources.
Any thoughts on why this conflict would exist?