Solutions For Os Clients - Siemens SIMATIC PCS 7 Function Manual

● Online help for
● Documentation on the Process Historian
● Section "How to configure a central archive server and its redundant archive partner
3.6

Solutions for OS clients

3.6.1 Additional OS clients
Additional OS clients
OS clients are PC stations that are used for control and monitoring of an automation process.
They are connected to the OS servers through the terminal bus. The OS servers form the
process connection to the automation system.
An OS client has its own WinCC project and visualizes the process data generated on an OS
server.
If an OS client fails, this does not disrupt the overall process because the automation program
in the CPU continues to control the process and the OS servers continue to process and archive
the process data. However, the visualization of the process is lost and you can only influence
the process through the OS servers. You should therefore protect against such failure by
integrating additional OS clients.
By specifying a preferred server, you can distribute multiple OS clients between the redundant
OS servers. The automation process can therefore be operated continuously, even during a
failover from the active OS to its OS partner server.
Additional information
● Section " How to configure an OS client (Page 144) "
● Online help for
3.6.2 Permanent operability
Permanent operability
"Permanent operability" in a redundant environment is the unrestricted ability to influence the
system at any time even when confronted with the failure of one of the redundant OS servers.
It is the most important safety characteristic for plants with critical operations.
This function is important in all systems in which the ability to handle failure of an OS server
in a redundant configuration is not enough and in which continuous control of a process must
be maintained. In the event of an OS server failure, all OS clients connected to the failed server
will temporarily lose their connection to the process while they switch over. In order to ensure
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02
WinCC ; WinCC Redundancy
server (Page 130)"
WinCC
Fault-tolerant Solutions in PCS 7
3.6 Solutions for OS clients
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