User Manual

Part A: System Overview
System Architecture - How the System is Organized
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The Desigo CC Database Service runs on the Desigo CC Server and connects to a
Microsoft SQL Server hosting the History Database (HDB).
HDB is used to log a wide range of records including:
● User and system activities, e.g. user log-in and logouts, access to applications,
monitored client connections, system restarts etc.
● Events, such as alarms and faults and their guided procedure steps.
● Field network activity such as, change of states, change of values, commands
● Trends and time series.
➜ For details about the range of logged user activities and system events, please
refer to the Reports section of the Desigo CC Help.
Databases setup
To reduce the load on the main server, Microsoft SQL Server can be installed on a
separate machine or in a virtual environment. Desigo CC can also use existing
customer-provided Microsoft SQL infrastructure.
Microsoft SQL Express is included on the product installation. If the system
requirements exceed the capacity of Microsoft SQL Express, Microsoft SQL Server
regular editions can be used, extending storage capacity and increasing the
performances of the history database operations. Procuring and installing Microsoft
SQL Server regular editions is not part of the Desigo CC offering. The software
licensing, administration, and maintenance of Microsoft SQL Server regular
editions is the responsibility of the customer.
Long Term Storage and Archiving
The History Database supports four standard archive groups, related to the record
types for events, value changes, activity and trends. All system objects store their
data in the specific archive group depending on the type of record. Data of the
standard archive groups are stored in “ring buffer” tables, meaning that, after a
configurable retention time, the overflow data is deleted to allow space for the new
data.
For Long Term Storage, the basic capability of the historic database infrastructure
is extended.
On top of the ring buffer tables, it is possible to configure multiple on-line stores. An
on-line store is a set of data-slices of configurable size or duration. Data is stored
in a slice for as long as the size or duration limits are met, then passing to the
subsequent slice. When the maximum number of configured slices is reached, the
data of the oldest slice is archived off-line. Offline archives can be remounted on
demand when old data needs to be available online for access from a Desigo CC
application.
This mechanism allows maintaining extensive amounts of historic data on line and
providing support for on-line data archiving and on-demand re-mounting.
Moreover, besides the standard archiving groups, Long Term Storage allows to
define custom archive groups.
A custom archive group allows assigning a specific subset of system objects and
record types to a specific store.
This feature is particularly useful when events, value changes, activity or trend
information for a part of the system require different retention times or simply need