GIS Connection Strings are created and modified within the Lucity Administration Tool. This is the connection that Lucity will try to use to recognize whether feature classes in ArcMap are configured to update Lucity. If the geodatabase is an SDE Lucity will also use this connection string to connect to and update the geodatabase, when changes are made in Lucity. (How those updates work are also controlled by other system settings.)
How to
Setup a GIS connection String
GIS > Connection Strings
. The following window will appear
Note: The GIS configuration supports having multiple geodatabases connected to Lucity at the same time.