Siemens SIMATIC PCS 7 Function Manual page 224

Archive management
8.2 C functions for export and backup
5. Data management as circular archive
– Data in the archive are not archived externally and are only available during runtime.
– If the archive is full (data records in the archive >= FULL_NO_OF_REC), the C function
6. Deleting of data with maximum archive size
If the archive is full (data records in the archive >= FULL_NO_OF_REC), the C function
"FB_ARExportTrigger0.pas" tries (without exporting the data) to delete the following n data
records one after the other (n := relevant cell in "DEL_NO_OF_REC" column in the
"FB_ARCHGROUP" archive):
– Step 1: x
– Step 2: Only performed if you are using an MES. If step 1 does not cover enough data
– Step 3: If the previous attempts do not cover enough data records, x
– Step 4: If there are still not enough data records, x
Access using an MES or similar system (without deleting the data records read)
Once a data record has been successfully read, the MES system must set the following flags
in the archive:
Access from AS
Once a data record has been successfully inserted / updated, the AS must set the following
flags in the archive:
REC_EXPORTED = 0
Once a data record has been successfully inserted / updated, the AS can set the following
flags in the archive:
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"FB_ARExportTrigger0.pas" deletes (without exporting the data) the n data records (n :=
relevant cell in "DEL_NO_OF_REC" column in the "FB_ARCHGROUP" archive) with
the smallest REC_ID (the n oldest data records).
data records (x
1
1. The smallest REC_IDs
2. Flag REC_FINISHED = 1
3. If applicable: Flag REC_READ = 1 (check MES value in the ini file)
4. Flag REC_EXPORTED = 1
records, the following x
also deleted:
1. The smallest REC_IDs
2. Flag REC_FINISHED = 1
3. Flag REC_READ = 1
<= n – data records deleted in step 1 x
deleted:
1. The smallest REC_IDs
2. Flag REC_FINISHED = 1
deleted in step 1 x - data records deleted in step 2 x
1
x ) are also deleted:
3
1. The smallest REC_IDs
REC_READ := 1
REC_READ := 0
<=n) with the following properties:
1
data records (x <= n – data records deleted in step 1 x
2 2
- in data records deleted in step 2 x
1
data records (x
3
data records (x <= n – data records
4 4
- data records deleted in step 3
2
Advanced Process Functions (APF)
Function Manual, 07/2016, A5E38719883-AA
) are
2
3
) are also
2