If DBDOC connects to your CIU using OPC90, then in order to run CIUMon automatically, you will need to run OPC90 automatically.
Recent versions of OPC90 can be run as a service. Running OPC90 as a service ensures that it is always available, both for CIUMon and for other programs that use it, such as a Composer or WinCAD EWS computer.
Older versions of OPC90 can be started automatically by CIUMon instead.