Lenze PLC Designer PLC Designer (R3-1) - Manual (Page 58)

L-force | PLC Designer
Lenze Specific Functions
56 DMS 4.1 EN 03/2011 TD29
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2.6 Data consistency during access to process image
Within a PLC project, several tasks can access the process image of a bus master.
Depending on the priority and cycle time configured, the tasks may interrupt one
another during this process.
The system only ensures data consistency for the access to data types of the following
length:
• Byte
• Word
• Dword
For bit accesses, data consistency is also ensured because here again uninterruptible
(i.e. atomic) commands are used.
The system, however, does not provide data consistency for accesses to data structures
(records). In this case, the user has to take appropriate measures.
Data consistency is achieved if only one task at a time accesses a certain data structure
in the process image for writing.