Item Mapping
A pre-condition for data retrieval is that replication is enabled in IP.21. In addition to the global setting, the IP.21 configuration allows to enable or disable replication for individual fields and repeat areas in a record definition. This is controlled by the PUBLISH_UPDATES setting. As part of the default IP.21 installation, a selection of fields of the built-in record definitions have PUBLISH_UPDATES set to true.
Inmation objects are mapped to IP.21 field values according to the rules described in this chapter.
| When changing the IP.21 replication configuration, changes will not be active immediately. The configuration changes are applied by the IP.21 Server component with a slow frequency (1 hour). To enforce a fast update, the IP.21 Server component can be restarted. |
Timeseries Repeat Areas
A record definition with timeseries repeat areas will be recognized during the Inmation browse operation, and an IO-Item will be created for each IP.21 record ("tag").
Additional timeseries repeat areas on the same tag, that have publishing activated, are created as IO-Property child objects during browsing. For example, with a default IP.21 configuration, the IP_AnalogDef record definition has PUBLISH_UPDATES enabled on IP_TREND_HI_LIMIT, IP_TREND_HIGH_HIGH_LIMIT, IP_TREND_LOW_LIMIT, and IP_TREND_LOW_LOW_LIMIT. This will create 5 Inmation objects: an IO-Item for the tag and 4 IO-Properties as children objects.
In the default mode, the ItemValue property for IO-Item or IO-Property is receiving the value of the IP_VALUE repeat area. Other behaviors can be controlled by the ItemValue Mode property, and the PUBLISH_UPDATES configuration setting in IP.21 system. This does, for example, allow to replicate data for IP_INPUT_VALUE instead of IP_VALUE.
Repeat Areas
Some record definitions have non-timeseries repeat areas. If publishing is enabled, during browsing these repeat areas are created as IO-TableHolder child object of the IO-Item. At the same time the value will be written on the TableDataAux property of the IO-TableHolder.
If the Server Type: IP.21 gRPC > Update on field changes property of the IP.21 gRPC Datasource object is enabled, configuration changes are applied directly to the TableDataAux property - for example, if new rows are added, or fields in a row are changed.
Static Fields
Specific IP.21 fields are mapped directly on Inmation object properties, according to this list. All other fields, that have publishing activated are inserted in the IP21FieldData property. During browsing, the value will be written on the relevant Inmation properties. Repeated browsing will read the value another time.
The datasource configuration setting IP21UpdateOnStructuredChanges allows to apply configuration changes directly to properties, without triggering a whole browse operation.