Data validation

You can have a warning message generated when a limit is violated during data entry. You specify such limits in the Data Validation tab on the central pane of the Tag Configuration window. The following data validation types are available:

• LoLo Limit. Checks a more severe low limit condition.

• Low Limit. Checks a less severe low limit condition.

• High Limit. Checks a less severe high limit condition.

• HiHi Limit. Checks a more severe high limit condition.

• Delta Limit. Checks the rate of change from the last archived value.

  Note: It is possible for multiple limits to be violated.

For each data validation type, you specify a limit by entering a quantity value or by selecting a PI tag from the Tag Search window, and then defining a trigger action in the Trigger Action Specification window.

Note: Because PI Manual Logger supports limits from PI tags, a limit can come from an external data source. For example, a PI tag that is configured to use RDBMS Interface or OLEDB COM Connector can access a data limit that resides in a relational database.

A tag can be used on multiple tours but may have a different limit in each tour. Additionally, the limit checking behavior for a tag can be different, depending on how each tour is configured. For details about configuring limit checking behavior, see Limit Checks tour options.