The data extensions are PROMOTIC system components, extending the basic functionality of
PmVar data items (variables).
Each data extension type is used for specific purpose (e.g. limit excess alarm,
OPC server or connection to the
PmaComm object, trends, etc.).
The data extensions can be defined in the "
Data extensions" configurator, in the configuration window setting the properties of one variable.
The principle of data extensions:
The data extensions are created (configuration and source part) in the
PmVar variable of the
PmaData object (
PmaCommGroup,
PmaOpcDaClientGroup,
PmaTrendGroup) object.
Most types of data extensions contain the reference to the
target object, where the data extensions register and are given the desired functionality.
For the target object, the data extensions act as
dynamické items, that are created and registered into the object after the application is launched, with automatic binding to the
PmVar variable value, where the data extensions are located.
The type of the target object depends on the type of data extension. For example
Note! It is possible to find and display all data extensions in the PROMOTIC system, that contain reference to a specific target object. See
List of data extensions.
Identifier #ext:
References to
Data extensions objects in the
PmVar variable can also be done directly by extending the path of the
Pm method using the
#ext identifier.
This can be used in the
Pm method or in PP binding
in the application and
in panels.
For example the method
pMe.
Pm("/data/#vars/Temperature/#ext/al") returns the data extension with
al identifier (
ExtAlarmAnalog) in the
Temperature variable (
PmVar) in the
data object (
PmaData object).
Identifier #vars:
The reference to
PmVar object can also be done directly by extending the path of the
Pm method by means of the
PmaData - Deatiled object description identifier. This identifier can be used e.g. in the
Pm method, or in the "
PP - Pma object property" data binding.
For example the method
Pm("/data/#vars/Temperature) returns the "Temperature" variable (
PmVar object) in the
data object (
PmaData object).
Format of saving the data extension in the form of a text string:
The content of complete of data extension (all configurators) can be saved in the form of single text string.
It is even possible to save content of all data extensions of one
PmVar object in the form of single text string, where each data extensions is separated by comma ('
,').
This is used for displaying a list of data extensions in development environment, but above all it can be used for export/import of
PmVar objects in
CSV form.
Syntax:
Id={DExtnType;Cfg1;Cfg2;…;CfgN}
The specific list and order of configurators is specified for each data extension.
List of data extension types: