The data extensions can be defined in the "Data extensions" configurator, in the configuration window setting the properties of each variable.
The data extensions are created (configuration and source part) in the PmVar item (variable) of the PmaData object (PmaCommGroup, PmaOpcClientGroup, PmaTrendGroup) object. Most types of the 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 starting the application, with automatic binding to the PmVar variable value, where the data extensions are located.
The type of the target object is based on the type of the data extension. For example PmaTrendGroup for ExtTrend, PmaCommGroup for ExtComm, PmaOpcClientGroup for ExtOpcClient or PmaAlarmGroup for ExtAlarmAnalog and ExtAlarmBinary.
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.
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).
The reference to PmVar object can also be done directly by extending the path of the Pm method by means of the #vars identifier. This identifier can be used e.g. for the Pm method, or for the PP data binding in the application and in panels. For example the method Pm("/data/#vars/Temperature) returns the "Temperature" variable (PmVar) in the "data" object(PmaData).
The contents of complete data extension (all configurators) can be saved as a single string.It is even possible to save all data extensions of one PmVar object as single 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.
The specific list and order of configurators is specified for each data extension.
|ExtAlarmAnalog||An extension for alarm the analog value|
|ExtAlarmBinary||An extension for alarm the value of the Boolean type|
|ExtComm||An extension for connection to the PmaCommGroup object|
|ExtDdeClient||An extension for connecting to the DDE server|
|ExtDdeServer||An extension for DDE server offering|
|ExtEvent||An extension for generating events|
|ExtOpcClient||An extension for connecting to the OPC DA communication.|
|ExtSubVar||Extending variable PmVar by subvariable|
|ExtTrend||An extension for connection to the PmaTrendGroup object|
|ExtWriteAction||An extension for invoking an event when writing a value|