ColumnList

Returns a list of the columns in the selected table. To select the table, use the Group parameter. The Mask parameter can be used to filter the list of columns returned from the query.

Current

Provides current values for discrete and analog tags.

FixedQuery

Requires the entire SQL statement to be passed through the Query and QueryParams parameters.

GroupList

Finds tag groups defined in the connector. The tag groups include the system-defined groups, such as All Analog Tags, All Discrete Tags, and so on, and user-defined public and private groups. The user ID and password used to connect to the database controls which private groups are displayed in the results of the query. This mode can be used with the Mask parameter, which enables you to return only those groups that match the mask pattern.

History

Provides interpolated historical values for analog and discrete tags. You can specify the number of rows or retrieval resolution for interpolation. If you enter a Resolution parameter value, the connector retrieves evenly-spaced values until the RowCount parameter value is reached. If you do not provide a Resolution parameter value, the connector returns an evenly-spaced number of values based on the RowCount parameter value.

For example, if the time interval is one hour, Resolution is 15, and RowCount is 240, the connector returns a value every 15 seconds until it reaches 240 values.

HistoryEvent

Provides historical values for analog and discrete tags as they are stored by the connector. This mode does not provide interpolated values.

Statistics

Ensures statistical measurement precision, especially for the time-weighted average, using the storage time and values from the historical database. When the connector is retrieving data for statistical calculations, it uses the same process as the HistoryEvent mode.

TableList

Returns the list of tables defined in the database. The Group parameter can be used to filter the TableList query to select only system tables, user tables, or views. The Mask parameter can also be used to filter the list of tables returned from the query.

TagList

This mode allows you to find tags defined in the connector. You can use this mode with the Group and Mask parameters. If you include a Group parameter value, tags for that group are displayed. You can use the Mask parameter to return only those tags that match the mask pattern.