7/21/2023 7:42 PM | |
Joined: 1/21/2013 Last visit: 9/10/2024 Posts: 3088 Rating:
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Hi, The handling and configuration of retentivity has changed between classic STEP 7 and TIA Portal. In classic programming an entire data block was either retentive or not, in TIA Portal (in case of optimized access, which is the default) you can specify retentivity for individual variables. So you have to be careful to activate it where it is needed. Due to limited memory for retentive data, it is usually not possible to set all data to retentive. For handling online data, such as storing an online value and writing it back to the PLC, you now have more options for using snapshots and setpoints. See the following chapters in the system manual:
Stefan |
7/23/2023 7:04 PM | |
Joined: 1/21/2013 Last visit: 9/10/2024 Posts: 3088 Rating:
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Hi, No, we will not assume that the logic was changed by a power failure. Since the load memory is a non-volatile memory - in the case of the CPU 1510SP F-1 PN the SIMATIC memory card - the data would not be lost. Even if changes are written, the old data is not replaced until the new data has been successfully downloaded. I can only see two possibilities why the program code is displayed differently after a power failure.
You should check the timestamps of the affected blocks. In case of a defective memory card an old timestamp will be displayed, in case of manipulation a newer timestamp will be displayed. Kind regards |
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