SIEMENS
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Siemens ST PCS 7 · 2017 (Preliminary edition)
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Design
(continued)
Operator System
Introduction
In this architecture, redundant OS servers may be set up to meet
higher availability requirements. Critical applications running on
the OS server are monitored by Health Check for software faults.
If a fault is detected, switchover to the redundant system is trig-
gered. Synchronization of the redundant OS servers takes place
automatically and at high speed.
OS clients can access the data of not only one OS server/server
pair, but from several OS servers/pairs of servers simultaneously
(multi-client mode). This makes it possible to divide a plant into
technological units and to distribute the data accordingly to sev-
eral OS servers/pairs of servers. In addition to scalability, the ad-
vantage of distributed systems is the ability to decouple plant ar-
eas from each other, which results in higher availability.
The OS servers are designed in addition with client functions
which permit them to access the data (archives, messages,
tags, variables) from the other OS servers of the multi-user sys-
tem. This means that process graphics on one OS server can
also be linked with variables on other OS servers (area-indepen-
dent displays).
Like the OS single stations, the OS servers can be connected to
the Industrial Ethernet plant bus using one of the following net-
work components
•
IE: CP 1623 communications module (pre-installed in
SIMATIC PCS 7 Industrial Workstation) or CP 1628 communi-
cations module for communication with max. 64 automation
systems
•
BCE: Standard Ethernet network adapter (10/100/1000
Mbps)
and Basic Communication Ethernet for communication with
up to 8 automation systems (no redundancy stations)
Two 10/100/1000 Mbps Ethernet RJ45 ports onboard can be
used to connect to the terminal bus.
Data archiving
The OS Single Stations and OS servers already include a high-
performance archiving system, configurable at run-time, based
on Microsoft SQL Server with cyclic archives for short-term ar-
chiving of process values (typically for 1 to 4 weeks) and mes-
sages/events (typically for 2 months). This may be combined
with an external data archiving system for long-term data stor-
age. The Process Historian offered in the section "Process data
archiving and reporting" is available for this purpose.
The archive data can be saved on all storage media supported
by the operating system, for example on a NAS drive.
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Technical specifications
1)
If every OS client has access to all OS servers/pairs of servers
Definitions
OS tag
An OS tag or parameter is a defined memory location
required for operating and monitoring with the operator
system; values can be written into it and read from it
(e.g. setpoint, actual value etc.).
Process object
(PO)
A process object (PO) is synonymous with an operable
and monitorable block. A PO usually has several OS tags
(which can be operated and monitored). The number of
OS tags differs depending on the block type. For example,
motors or valves require fewer tags than closed-loop con-
trols or dosing units.
Licensing
Licensing and license verification of the OS software for
SIMATIC PCS 7 are based on the process objects.
Every block fulfilling the following criteria is counted and
calculated as a PO:
• The block is not a driver block.
• The block can be operated and monitored.
• This block can handle messages.
The license verification also takes into account the sum of
all OS tags used.
OS quantity framework
Max. number of OS single stations
8
Max. number of OS servers/pairs of
servers
18
Max. number of automation systems
per OS server/pair of servers
64
Max. number of OS clients in multi-
client mode
1)
(per multi-user system)
40
Max. number of monitors per operator
station with multi-channel operation
4
Max. number of OS areas
64
Max. number of windows per monitor
1 to 16 (adjustable)
Number of trends per trend window
10
Selection time for OS area display
(100 process symbols)
< 2 s
Max. number of process objects:
• Per OS single station
8 500 POs
• Per OS server
12 000 POs
Max. number of configurable mes-
sages per server/single station
200 000
Number of process tags
• Per OS single station
approx. 5 100
• Per OS server
Approx. 7 000
• Per multi-user system
Approx. 126 000
Integral high-performance
archive system
(cyclic buffer), based on Microsoft
SQL server, for:
• Process value archiving
(per OS server / single station)
Approx. 1 500/s
• Message archiving (per OS server /
single station)
Steady-state load approx. 10/s
Message peak approx. 3 000 / 4 s
© Siemens AG 2017