From OpenSCADAWiki
The tab "Archive" (Fig.4.6d) contains the basic settings of the archive:
- Section "State" — contains the properties, which characterize the state of the archive:
- Running — state of the parameter "Running". Running archive collects data in the buffer and is served by the archivers.
- Begin and end of the buffer — date and time of values begin and end into the buffer.
- Storage — the archive's data storage, with tracking the availability of the data in different storages and providing the sequentially removing duplicates.
- Section "Configuration" — directly contains the configuration fields:
- Identifier — information on the archive identifier.
- Name — specifies the archive name.
- Description — brief description of the archive and its purpose.
- To start — indicates the state "Running" in which to transfer the archive at the program startup.
- Source — indicates the type and address of the source. Type of source is indicated from the list: "Passive", "DAQ Attribute" or "Active DAQ Attribute (DEPRECATED)". Passive archive does not have an associated source of values, the data to the such archive the source transfers by itself, for example from calculating procedures of users on internal programming language. Types with the attribute of the parameter in the address field indicate the parameter attribute of the subsystem "Data acquisition" as the source. Main attribute of the parameter sends data to the archive by itself with its own period of the data acquisition. Active attribute of the parameter is acquired by the archiving task of this subsystem. All real data sources work in the main archiving mode since the received data is immediately placed in the parameter attribute, sometimes by the source timestamp. The calculators (DAQ.JavaLikeCalc, DAQ.LogicLev, DAQ.BlockCalc, DAQ.Siemens, DAQ.OPC_UA) also works now in the main archiving mode and early used the active archiving mode because the data in the attribute parameter was updated only with them direct request, and was taken from the execution context. In the case of the real data sources, the difference between active and main mode of archiving by the fact that in the main mode the source can put data into the archive by timestamp, and in the active mode the timestamp is always set to the current system time.
- Data combining mode — sets the combining mode for data writing from the high-resolution buffer (for example, 1 second) to low-resolution archiver (for example, 1 minute), when into single point of the archiver placed several values (for example, 60) from the buffer. The modes implemented: "Moving average", "Single", "Minimum" and "Maximum".
- Value type — indicates the type of values which are stored in the archive from the list: "Boolean", "Integer", "Real", "String", "Int16", "Int32", "Int64", "Real(Float)" and "Real(Double)".
- Buffer period — indicates the periodicity of values in the archive buffer, in seconds.
- Buffer size — indicates the dimension or depth of the archive buffer. The dimension is automatically sets at a rate of 60 sec of the periodicity of the archiving task, with the remainder.
- Buffer in the hard time grid — indicates the mode of the buffer. The hard time grid mode involves the memory reservation for each value, but without the timestamp. This mode eliminates the possibility of packaging the adjacently-identical values but also saves on storage of the timestamp. Otherwise, the buffer operates in the mode of storage the value and timestamp and supports the packaging of adjacently-identical values.
- Buffer in the high time resolution — indicates the possibility of storing values at intervals and dimensions up to 1 microsecond, differently the values can be stored at intervals and dimensions up to 1 second.
- Filling the passage points with the last value — the passage values mostly fill by EVAL but sometime data periodicity of the source greater to the archive's one and it is normal.