3/18/2023 2:58 PM | |
Joined: 3/28/2015 Last visit: 4/19/2024 Posts: 721 Rating: (213) |
Hello, Perhaps the following FAQ might help: |
Eng.Mohamed Ibrahim |
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This contribution was helpful to1 thankful Users |
3/26/2023 8:02 AM | |
Joined: 3/30/2020 Last visit: 4/26/2024 Posts: 4455 Rating: (931) |
The old code needs to be removed first before the changed code can replace it, if the memory card is small. There are ways to try and avoid a CPU stop. But it is not very practical. So yes - - the PLC will need to stop. (rough process) A changed block is loaded in unused memory. At the start of the next PLC cycle, the calls of the code block points to the newly loaded memory. The memory location of the original code block is marked as unused. Some de-fragmentation process occur to optimize the memory usage -- which also needs some extra memory. (In the older generation CPUs this had to be triggered manually.) Keeping the FC/FB blocks small and compact helps a little. That means the 'buffer' required to load the changes does not need to be as big. After (very) many changes the used memory space may grow more than it needs to. Then a restructure & compile and reload with CPU in stop will be needed. Having a big memory card gives a good excuse to not needing to know how the memory regulation process take place. EDIT |
Last edited by: qwazee at: 03/26/2023 08:05:50Activities of this user is voluntary. There is no obligation or liability placed on this user. Though optional, your 'please' and 'thank you' is highly valued. |
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