Data point type, master data point and data points

As mentioned in the introduction, the master data point is the central element in mass configuration. This page aims to provide essential information on creating and configuring a master data point for mass configuration.

One or more data points are created in the database of the WinCC OA system on the basis of the master data point. All configuration settings for the master data point are transferred to a new data point when it is created. Subsequent changes to the master data point are transferred automatically to data points at runtime. If PowerConfigs containing dynamic attributes are added to the master data point, then changing a dynamic attribute does not result in this change being adopted by existing data points. Settings for dynamic attributes must be made using PowerConfig configuration at the data point.

Before you can create a master data point or data point at all, a data point type must be defined specifying the structure and data types of the leaf elements. The chapter PARA/Create a data point type contains further information on creating a data point type.

The renaming of a data point type or node in the structure, with presence of a master data point, is not supported by the Dp-Type-Editor. Since the name of the master data point consists of the data point type name (see below), the mass configuration would not work anymore in case of changing the type name! The changing of the data point type structure (insert, delete node) can be performed at any time.

Once you have defined the structure of your data point by creating a data point type, your next step can be to add the master data point. To do this, right-click on a data point type and select the option Create master data point in the context menu that opens.

The figure below shows the context menu:

The name given to the master data point is constructed as _mp_ + data point type name. A gray folder symbol with a red point on the left side below, indicates a master data point in the PARA module.

Of course it is not an essential requirement to create a master data point. After defining a data point type you can create just one data point (see also Creating a data point) or multiple data points (see also Creating multiple data points).

The major drawback in creating multiple data points without an existing master data point is that changes are not transferred to all the data points (apart from those made at the data point type itself). Thus each data point would need to be provided with configs and configured individually. Another disadvantage is that it is also not possible to work with PowerConfigs if there is no master data point. By inserting a PowerConfig (for example, alert handling with 3 ranges) at the data point element of the master DP, the configured settings are transferred to all existing data points (only dynamic attributes can be changed). If the master data point is subsequently deleted, the "alert handling" Config can then be changed in any way for each data point (ranges, limits and alert classes can be configured to suit). When a new master DP is created, this contains no alert-handling Config. Re-inserting a PowerConfig for alert handling, and setting the parameters in the master DP, once again transfers the settings to all the DPs, so that the parameters changed previously on the individual DPs are lost. The user must be aware of this process and take care when deleting and creating a master data point in order to avoid producing inconsistencies in the project.

In order to guarantee that the mass configuration works properly and that there are no inconsistencies in the system the configs always have to be configured via the master data point. Afterwards the data points can be created. If the master data point is deleted or created when data points exist problems with the mass configuration and the already existing configs may occur!

When working with the mass configuration facility in WinCC OA, always use the functions/panels provided (Creating multiple data points, Deleting multiple data points, PowerConfig configuration, Templates/DP lists, Excel tools). Avoid making changes using CTRL scripts you have written yourself, external database tools, exporting and importing DP lists in standard format using the ASCII Manager or the like, as this can lead to inconsistent states in the system.

Define the master data point for a data point type and provide this with Configs (for more details of the data point Config refer to PARA Module/Data point configs, basics) and PowerConfigs (more details in PowerConfigs, basics). Configure these Configs to suit your requirements. If multiple data points are created after configuration then these are derived from the master data point and have the same settings. Any changes to the master data point (for example, adding a Config, modifying the values set in a Config etc.) have the same effect on all data points of this type at runtime.

The Transfer to all DPEs option in the context menu of the master data point (right-click on the master data point) updates all data points with the configs and configurations set in the master data point. A confirmation prompt appears before the transfer is made to all DPEs, however. Use this function to maintain consistency in the system. Use the option "Transfer current level configs" (right-click on a datapoint node) to transfer the configs of the selectednode to all datapoints. All other elements are not changed. To transfer one selected config of an element, use the option "Transfer selected config" (right-click on a datapoint element). This specific config of an element is transferred to all datapoints.

Example

In the example below the "_archive" as well as the "_alert_hdl" configs of the "alert" node of the master datapoint _mp_DRIVE1 are transferred to the alert node of the "Drive1" datapoint by using the option "Transfer current level configs".

The configs _common and _lock are not transferred by using the option "Transfer current level configs".

Figure 1. Node "alert" and the Configs of the Node
Figure 2. "Transfer current level configs" Option for the DP Node "alert"
Figure 3. The "_archive" as well as the "_alert_hdl" configs of the "alert" node are transferred to the alert node of the "Drive1" datapoint

Example

In the following example, the _alert_hdl config of the datapoint element "controlFuse" of the master datapoint _mp_DRIVE1 is transferred to the datapoint element "controlFuse" of the "Drive1" datapoint.

Figure 4. The _alert_hdl config of the datapoint element "controlFuse"
Figure 5. The "Transfer Selected config.." Option "_alert_hdl"
Figure 6. the _alert_hdl config of the datapoint element "controlFuse" of the master datapoint _mp_DRIVE1 is transferred to the datapoint element "controlFuse" of the "Drive1"

The PARA module has been provided with new functions for mass configuration (context menus, appearance of the tree structure). You can change back to the "old mode" at any time as follows:

  1. Open the panel <wincc_oa_path>/panels/para.pnl in GEDI.

  2. In the panel, click on the ActiveX object in the tree view and switch to the Events tab.

  3. Open the Initialize script.

  4. There are 2 comment lines in the middle of the script. Remove the two "//" from the second comment line and click on OK in the Script Editor.

  5. Save the panel and restart the PARA module.

The "old" PARA module is now available again (in this case mass configuration can no longer be used). It is necessary to change the PARA module if you have previously already used master data points and then want to use the functions of the earlier configuration module.