Siemens ST PCS 7 manual 10/16, Function

© Siemens AG 2008

Automation systems

Fault-tolerant automation systems

Individual configuration of AS bundles ■Function

The equipment of the fault-tolerant automation systems as well as their Order Nos. can be individually compiled by selecting preconfigured ordering units. System-specific ordering configu- rations are available for this purpose in the following Section "Selection and ordering data".

These are divided into:

•Single stations: AS 412-3-1H, AS 414-4-1H and AS 417-4-1H with only one CPU, e.g. for the following cases:

-Subsequent expansion to a redundant system

-Redundant configuration on UR1 racks, comprising 2 Single Stations, 4 sync modules and 2 sync fiber-optic cables

•Redundant stations: AS 412-3-2H, AS 414-4-2H and

AS 417-4-2H with two redundant CPUs, mounted on one com- mon rack (UR2-H) or two separate racks (UR2)

In order to rapidly access the recommended preferred configu- rations, these are additionally listed with their complete Order Numbers.

As an alternative to the ordering data in this catalog, the configurator offered in the catalog & online ordering system "A&D Mall" (www.siemens.com/automation/mall) can also be used to select and order fault-tolerant automation systems for

SIMATIC PCS 7.

Ordering information:

For a redundant configuration based on 2 Single Stations, you additionally require 4 sync modules (up to 10 m or 10 km) and 2 fiber-optic sync cables. Their selection depends on the dis- tance between the two Single Stations.

The AS 412H (AS 412-3-1H/AS 412-3-2H) automation systems currently only support sync modules with a range up to 10 m. Fiber-optic sync cables longer than 1 m must always be ordered separately (2 of each required).

The fault-tolerant automation systems of SIMATIC PCS 7 are based on the 1-out-of-2 principle. In the event of a fault, they switch over to the standby system. These systems use a com- pletely redundant design to maximize availability. Therefore all important system components are present twice, such as:

•Central processing unit

•Power supply

•Hardware for linking the two CPUs

Which other components are also made available in pairs in the interest of availability depends on the application-specific sys- tem architecture.

The two subsystems of a redundant automation system are elec- trically isolated from one another. This increases the system sta- bility with respect to electromagnetic interference.

The firmware of the fault-tolerant automation systems can be up- dated in two ways:

•Per Flash-EPROM memory card (8 MB)

•From the central engineering system via the Industrial Ether- net plant bus

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Siemens ST PCS 7 · Update November 2008