OS single stations and OS servers can have a redundant design if necessary. The following program packages are available:

• SIMATIC PCS 7 Single Station Redundancy for setup of redundant OS Single Stations
• SIMATIC PCS 7 Server Redundancy for setup of redundant OS servers.

For optimizing internal communication, connect the two stations of the redundant OS Single Station/OS Server pair to each other either via an RS 232 connecting cable or via an Ethernet cable, e.g. cross-over network cable with RJ45 connectors (up to 100 m). The cable material is to be ordered separately in each case:

Depending on the environmental conditions and the distance involved, the Ethernet connection between the two redundant stations can be implemented either as an electrical or optical connection. For more information, refer to the "SIMATIC PCS 7 High-availability Process Control Systems" manual; for suitable cable material and further accessories, refer to Catalog IK PI (Industrial Communication).

What further components are required depends on the plant architecture. The design of the plant bus and terminal bus is of particular importance, as well as the type and number of subordinate automation systems. The maximum requirements are determined by the redundant configuration shown in the figure with a fault-tolerant automation system and two redundant rings each for the plant bus and terminal bus.