800xA Multisystem Integration makes it possible to operate or supervise several 800xA systems from one central system. This gives users central operation of several 800xA DCS systems. In addition the multisystem integration function can be used as an 800xA Enterprise Information System. In this case all operational information for all provider systems are available with read only access from any office desktop without any need for local installation on the desktop computers. To secure the connection between the office network and control system networks we use demilitarized zones (DMZ).