4/19/2017 7:02 PM | |
Joined: 6/5/2009 Last visit: 9/21/2024 Posts: 150 Rating: (0) |
Dear All, To generate a data log in the CPU DataLogCreate was used and to write data the DataLogWrite is required, To append the data to a new record DataLogNewFile is used by retaining the same ID. My question is : when the new data record is full, how do I write in the old record. How do I use these 2 files cyclically. Can you suggest please. Also once the new record has been written fully what would happen to the older record and the new record. If some has a cyclical method of using the records, request you to share the idea. Best Regards, Grim Reaper |
4/20/2017 10:41 AM | |
Joined: 6/5/2009 Last visit: 9/21/2024 Posts: 150 Rating: (0) |
Hi JLaege, Thank you for the reply. I got the concept of the ring wrapping of data. Every time the file is fully written the queue operation is followed to replace the older records. When I need the data to be written to a new file "DataLogNewFile" function block is triggered and the new file is created. Once Created, and opened the data is pushed to the new file. If no more new files are created then the data in the latest created file is over-written over and over again, replacing the older records in the latest created file. The requirement from my customer is that... 1. Data records created on the CPU should not be deleted. They should be retained continuously. 2. Older records should not be replaced. New records should be created on a continuous basis. 3. Present volume of the records created is 4320 (10 min per hour for a month = 6*24*30). To match the volume of data, 24MB MMC has been installed in the S7-1200 CPU. 4. I can try to convince the customer to have 2 such records, in order to retain the previous month's data, however when both the records have been fully utilized, the latest record should not be overwritten, however the older one has to be overwritten. 5. The storage of data should be cyclic with reference to both the records : Meaning :- If the older record is filled, then the newer record should start. Once the new record is filled, the older record should be rewritten. With the help of "DataLogNewFile" the new record is created, however it is the only record being referenced and written to. Can any further suggestion be given regarding this. Hope that it is possible to fit data like how I requested. Regards, Grim Reaper. |
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