[NextGenArch]

Settings for the NextGenArchive (NGA)

[NextGenArch] backendRestartDelay

Type
uint
Default
20
Allows to configure the delay (in seconds) between the startup attempts of the database backend.

[NextGenArch] importSourceDbAsIso

Type
boolean
Default
0
Range
0|1

In the case of importing a non-project-specific, historical WinCC OA database, which is ISO-coded, you must manually add this configuration entry to the configuration file of the new project by setting it to [NextGenArch] importSourceDbAsIso = 1.

[NextGenArch] maxSecondsToWaitForInitialQueriesBeforeConnectingToEvent

Type
uint
Default
60
Range
Seconds
Unit
Seconds
Specifies the time how long the error messages (that the EVENT manager was not started) are suppressed in NGA. The value must be as high as the time that EVENT manager requires in order to start.

In general changing this entry is only required for larger projects where the start of the EVENT Manager may take some time. Directly connecting to the EVENT Manager without this delay would cause the log to be filled with "cannot connect to event manager" messages.

NOTE: The EVENT Manager connection can still be configured as before by using the config entries connectDelay and connectRetries.

[NextGenArch] timeoutForAlertReadConsistency

Type
int
Default
30
Unit
Seconds

When a manager uses a historical query to query a time range that is currently being written to and there are pending buffers that the backend/database needs to write, NextGenArch waits for the pending writes to complete.

After the timeout "timeoutForAlertReadConsistency" expires, the query request is sent.

The timeout specifies the maximum time waited between "the query is started" and "the values are available in the database". If the time "between the query is started" and "when the value is available in the database" is shorter than the specified timeout, only the needed time is used and not the maximum time.

This is most notable when using the alert and event screen in open mode, when new alerts are constantly generated.

Use this entry to specify how long you can wait for the query result:

  • Use -1 if you can wait indefinitely. It guarantees read consistency.
  • Use 0 when you cannot wait. This disables read consistency checks and is therefore not recommended.
  • A value < -1 is ignored and the default value 30 is used instead.

This applies to all managers that execute an alert query. This only applies to alert queries that do not use DirectRead. Since DirectRead does not have access to the data that still needs to be written, DirectRead cannot perform read consistency checks.

[NextGenArch] timeoutForEventManReadConsistency

Type
int
Default
30
Range
Seconds
Unit
Seconds

When a _dp_fct query from the event manager queries a time range that is currently being written into the database, it has pending buffers that the Backend/Database must still write. The NextGenArch will wait at maximum the "timeoutForEventManReadConsistency" time for the pending writes to be completed. After the timeout has expired, the query is sent away even if the values ​​are not written. This can cause inconsistent results in the _dp_fct since the event manager expects that the _dp_fct will consider recent dpSets.

  • Value 0 disables the read consistency checks (not recommended).
  • Value -1 specifies an infinite timeout and guarantees read consistency.
  • Values smaller than -1 are ignored and the default of 30 is used instead.

This only applies to queries from the event manager via _dp_fct configs. All other queries (CTRL, UI or custom managers) are not subjected to read consistency checking.

[NextGenArch] triggeredArchiving

Type
int
Default
0

Allows to define the behavior for triggered archiving. A triggered archiving is performed, if the _archive config is set active. In this case all DPEs of this archive configuration are handled as if they received a hotlink with the current value.

Note: Can only be used for DPEs that have a _archive config.

Possible settings are:

  • 0 - default; Triggered archiving is not performed.
  • 1 - When the value is sent to the backends, the latest timestamp of the DPE is used.
  • 2 - When the value is sent to the backends, the timestamp of the dpSet() operation is used.

[NextGenArch] useOriginalValue

Type
int
Default
0
Range
0|1
0: NGA connects to _online values as before. The behavior is unchanged. 1: NGA connects to _original values instead of _online values. This changes the meaning of the columns in the database as _original values are now archived instead of _online values.

The config entry can be used for large data point structures that contain many sub elements since NGA connects to all _online configs and the EVENT manager becomes slower.