General

With WinCC OA Version 3.20, the handling of deactivated _alert_hdl configurations has been changed. In previous versions, even if the alert handling was deactivated, the Event Manager still provided alert previews.

To increase the overall performance of WinCC OA, this behavior has now been disabled and no alert previews will be generated.

Since the behavior of the earlier versions was also used in other areas of application, e.g. in order to use a text-attribute (_offline..text) to obtain additional information for value changes in historical queries, it may be necessary to reactivate this for your use case.

To reenable the behaviour of older versions, the config entry [event] enableAlertPreview can be set.

[event]
enableAlertPreview = 1

As of WinCC OA Version 3.20, the DP Comment in the _common config is split into the sections comment, format and unit. This ensures easy handling of translatable content with the translator tool in the future

Starting with 3.19, the bearer plugin was removed for all Linux-based builds.

Regarding the JSON format, we took customer feedback seriously and optimized the format. However, we could not completely ensure compatibility.

Since vimacc version 2.2.2.2 (installed with WinCC OA 3.15) IPC sockets encryption is enabled for all vimacc services. Unencrypted WinCC OA components cannot communicate with the encrypted vimacc services anymore. This means that:

• A video server with this vimacc version cannot be operated with video clients from Versions lower or equal to 3.14, since you cannot enable encryption for them.
• The vimacc version of an existing video server is also updated.
• After installing a WinCC OA Version higher or equal to 3.15, it is not possible to communicate with encrypted vimacc services in an existing WinCC OA project from a Version lower or equal to 3.14. This also applies if the services are running locally.

Starting with version 3.18, the functionality of "webclient_http.ctl" was moved to the new CTRL++ class "HttpServer" in "HttpServer.ctl". "webclient_http.ctl" was modified to create an instance of this class and call the "start()" function. This allows you to easily add new httpConnect() calls in "webclient_http.ctl" or derive new classes from "HttpServer". It is, however, still not possible to create more than one instance of an "HttpServer" per script. This also means only one instance of the "HttpServer" class is possible.