OPC HDA group properties

MaximumTimeDomain

The maximum period that a request from the OPC HDA connector can cover. Depending on the configuration, the connector can poll from the end of the sample stream or from the last sample. Regardless of which point the connector polls from, it polls tags every poll interval for a period that is no longer than the MaximumTimeDomain property until the connector is up-to-date.

Note: If you specify a status variable that is an OpcHdaStatusVariable item, AVEVA™ Production Management ignores the MaximumTimeDomain setting of the group.

[hh:mm:ss]

Offset

The difference from the current time when making requests from the OPC HDA system.

[hh:mm:ss]

OpcHdaDataSource

This value is display only. It is the path structure and name, in dot notation, of the data source that the connection belongs to. It represents the position of the item in the project hierarchy. The full name identifies the data source in code.

PollInterval

The frequency at which AVEVA Production Management polls the OPC HDA server. Set the PollInterval to a value greater than the scan rate, which is the time that data takes to make a round trip (from request to reply). The speed and activity of the network and system can restrict the poll interval. Alter the setting of this property with consideration for system performance maintenance.

Without a specified status variable, the OPC HDA connector attempts to poll tags in a group in one request. With a specified status variable, the OPC HDA connector monitors the status variable at the configured poll interval, and if the value for this variable changes, AVEVA Production Management makes a request for variables in the group that uses the status variable.

[hh:mm:ss] Minimum is 1 second (00:00:01). Maximum is 23 hours, fifty nine minutes, fifty nine seconds (23:59:59)

StatusVariable

(Optional). The variable that an OpcHdaGroup item can use to define the point up to which AVEVA Production Management can poll the variables in the group. This can be any variable, such as a stored variable, calculated variable, or a tag on the OPC HDA server.