Configuration of the communication with eWON
This preconfiguration can be activated when creating a new object (e.g. by "New object ..."
in the local object menu or by pressing the Insert
key after selecting the object) and is included in the group: "/ Communication / PLC devices and meters / eWON - PLC device"
This preconfiguration can be created in the object: PmaFolder
The preconfiguration creates an object of the PmaFolder
type containing three subfolders
View - allows processing data in requested range from individual devices that are stored in cloud service Talk2M DataMailbox
Trend - allows reading and local storage of complete history of selected values from devices registered in the cloud service
Cfg - creates administration screen that can be used in order to create configuration file for trending selected values
In the "GetAuthentication"
method of the main eWon folder
there are all login entries requested for cloud service access.
" test panel is used for displaying received data. Here it is possible to use the configurators in order to put together requested method and command parameter. The PanelTrend
object allows rendering graphic chart of data in defined time-range.
object has methods RequestEwons
that are used to initiate the communication. Each of these methods call the Add
method of the PmaSequencer
object together with corresponding parameters. It triggers the onStep
event of the PmaSequencer
object where the HttpRequest
object executes the communication with the service. The received data is then processed by methods ReplyEwons
that must be modified accordingly.
Subobjects in this folder can be used to select values that will be read and saved locally into the database table of trends. The CfgTrend
panel is used for data selection and configuration. Once the configuration is saved, new file named "EwonCfgTrend.txt
" is created in the Cfg
folder of the application. The content of such file is necessary for correct functionality of subobjects located in the Trend
object. These subobjects are responsible for saving selected values into trends.
Subobjects in this folder are responsible for communication and saving selected values into trends. The configuration file EwonCfgTrend.txt
is necessary for their correct functionality. The file contains JSon
data created by the CfgTrend
panel. If increasing the number of trended values is needed, it can be done by opening the application in the development environment and copying the TrendVar1
object in the Trend
Once the communication is launched for the first time the application starts reading all historical data (stored in the cloud) of variables defined in the configuration file. The order of variables is respected. The data is read and stored continuously from the oldes to the newest. The application reads batches of 200 records every 0.5 seconds (after the previous batch is processed). Once one variable is fully read then another follows. This process may take significant ammount of time based on the total ammount of data to be read. Once all the data is read and saved locally following communication is planned for the time defined in the DataCfg
object in the Period
variable. This value defines for how many seconds the system waits (after the previous communication ends) before the next reading of data from the cloud is initiated.
These configurators can be set before the preconfiguration is created:
|The name of created object||Name of the object created in the Pma objects tree. The maximum name length is 30 characters. This is a system name, so it must contain only alphanumeric and must not contain any diacritics (i.e. national dependent characters), empty string, spaces and the first character must not be a number.
|Service account identifier||assigned identification code of service account|
|Token||User account token|
|Demonstration of the communication and data processing||Creates View folder for demonstration and testing of the communication and data processing|
|Save selected values into trends||Creates folders Trend and Cfg for configuration and trending of selected values|
|Number of trended values||Planned number of trended values|
|Data reading time period||The period (in seconds) of repeated data reading