The building block observation of AWL instructions has been improved

Update V3.1.4 for 6ES751x-xxx03-0AB0 and CPU1516T(F), CPU1517 and CPU1518 (without MFP)

New features with firmware V3.1.4 for all S7-1500 and ET 200 CPUs:

• TransferSubscription:
  The OPC UA specification specifies that OPC UA clients a subscription with their Monitored Items from one session to another session (see OPC 10000-4: UA Part 4: Services).
• The OPC UA server of an S7-1500 CPU supports the transfer of subscriptions from firmware version V3.1.4.
• Configuration for the S7-1500 OPC UA server is not required, the Service "TransferSubscription" is delivered at the request of an OPC UA clients.

User Experience Improvement:

• An improvement in cycle time has been achieved in the Overloading building blocks that use functions such as GetSymbolPath or GetSymbolName contain.
• The building block observation of AWL instructions has been improved.
• Observing the block of STRING REPLACE Instructions have been improved.

The following behavior has been fixed:

• A MC_MoveRelative solves a MC_GearInVelocity always off.
• If there is a SyncMaster redundant SyncMaster in the SyncDomain, the paired IO systems are after restarting the SyncMaster.
• The absolute value position of a Technology object with absolute encoder on an optional drive device also works after RUN -> STOP -> RUN and calling the function again ReconfigIOSystem no longer lost.
• At Netzein in the Profinet configuration "Multi-use IO system" together with Taksynchronität, the error message no longer occurs sporadically:
  -
• Temporary CPU Error: Fatal Firmware exception error (internal system code: 16#00090000 16#10020000 16#00000000) CPU enters DEFECT state
• It is no longer possible to have a custom server interface value changes from a variable to that are not listed in the DB as "Reachable from HMI/OPC UA/Web API" .
• When observing individual bits within more complex data types (e.g. Integer.%X4) than boolean, the displayed value deviate from the actual one.
• Fixed an issue where companion values were not resolved correctly in motion alarms or program alarms, and were therefore not displayed in the web server.
• Fixed an issue where resources, necessary for the establishment of the connection, sporadically in load situations have not been released. As a result, the PLC could not was more achievable.

Closed security gaps:

• Unlimitedstorage growth through session processing in TLSv1.3 in OpenSSL.
• The SIMATIC S7-1500 CPUs are protected by the vulnerability Memory growth affected by session processing in TLSv1.3 in OpenSSL (CVE-2024-2511). The weakness was disclosed 04/08/2024 at https://openssl-library.org/news/secadv/20240408.txt.

The vulnerability was found in CPUs of the SIMATIC S7-1500 product family with firmware V3.1.4 closed.