Define the Acceptable Limits for Historic Data Files

Geo SCADA Expert organizes historical data into granules. Each granule is stored in its own file on disk. Geo SCADA Expert can process and store several kinds of historic data. The granule content differs for each one:

The Stream Size is intended to be set up and changed only during the commissioning phase. If you have to change the Steam Size on a deployed system, you HAVE to perform the initial stream size transformation on a fully isolated stand-alone server. For more information, see Define the Stream Size for Improved Performance.

Alarm Summary

Each granule contains the alarms associated with a block of items in a one hour period. The blocks of items are determined by the alarm summary stream size (see Define the Stream Size for Improved Performance).

Configuration Changes

Each granule contains an audit of the changes made to a block of database items in a one hour period. The blocks of items are determined by the configuration changes stream size (see Define the Stream Size for Improved Performance).

Event Journal

Each granule contains the events associated with a block of items in a one hour period. The blocks of items are determined by the Event Journal stream size (see Define the Stream Size for Improved Performance).

Historic Data

Each granule contains the historic data for one stream of one point / accumulator in a one-week period. There are four streams of historic data called Raw, Modified, Annotation and Suppression, but only Raw and Suppression support overactive alerting (see Historic Data Storage Settings).

If a granule becomes very large it can affect the performance and reliability of the system. The Historic Overactive feature provides a way of alerting you should an individual granule become too large, allowing you the opportunity to take action to prevent it becoming excessively large and having an adverse affect on the system. The feature also limits the maximum size of each granule. Once a granule reaches the maximum size all further records for the granule are discarded.

NOTICE

LOSS OF DATA

When a granule reaches the specified maximum size all further records for the granule are discarded. This will result in the loss of data. To help prevent loss of data, you need to set appropriate maximum values.
Failure to follow these instructions can result in loss of data.

Geo SCADA Expert allows you to raise alarms for Alarm Summary data, events and configuration change files that reach a configured limit. For information on how to specify the criteria for these alarms, see the topics that are listed in the gray footer section at the bottom of this topic. Select the relevant entry to display the topic that you require.

Further Information

Historic Configuration Settings.

Operational Limitations (Client).

Operational Limitations (Server).