Which products are affected?
ESP-DDS2-x (Global Drive PLC Developer Studio Version 2.2)
Function description
If several tasks are defined in one DDS project, data inconsistency can occur if the same variables are used in different tasks and if these variables cannot be read or written by accessing them via the processor due to their data type.
The
Target Settings (tab:
Resources) have been extended by the option
Data consistency for multi-tasking. If this new option is activated, the data consistency for the following data types is guaranteed:
- DWORD, DINT, UDINT, REAL, TIME
- BOOL, if theses data type variables have an absolute address, e.g. bMyBool AT %MX0.0:BOOL;
If this option is active, a task with a higher priority cannot interrupt writing or reading accesses to a variable with one of the data types mentioned above.
Important:
By activating this option the run-time behaviour of a project changes. If a project created with DDS version 2.0 or version 2.1 is compiled with DDS version 2.2 and if the option
Data consistency for multi-tasking is activated, the run-time behaviour can change in such a way that a task overflow occurs.
Attention:
If projects created with DDS version 2.2 are opened in DDS version 2.1, the option
Data consistency for multi-tasking is not supported by DDS version 2.1. If this option was activated in DDS Version 2.2, data consistency errors and a changed run-time behaviour can occur when compiling with DDS Version 2.1.
