Question:
Is data consistency ensured during write access to LReal variables (64-bit) with Lenze controllers if the variables are simultaneously accessed from different tasks (multi-tasking system)?
Answer:
Yes, it is. Data consistency is ensured during write access to LReal variables (64-bit). Lenze controllers (3200C, p500) use 'atomic' data access which cannot be interrupted.
For array variables composed of several variables, data consistency must be ensured by corresponding programming in the controller program (keyword: semaphores). At least, if data consistency shall cover the entire array as a whole. Otherwise, without additional programming, data consistency will only be ensured for the individual array elements.
Search terms: Multi-tasking, consistent
