Source When Bad

Allows the value and data quality to be overridden when the value quality is bad when the Data Source is set to OPC Item, Tag, Calculation, or UDP Client Tag.  The following are the 3 available options for Source When Bad.

•      Normal Bad Quality: When the data source is bad quality the result is bad quality.  With Calculations any one of the source tags in the calculation being bad quality will cause the result to be bad quality.

•      Set Sources To Default Value: When the data source quality is bad the source value is overridden to be what is set as Default Value with the data type of Default Value Type.  With Calculations that have multiple tag parameters as a source each individual tag value in the calculation will be set to the Default Value when its individual data quality is bad.  This will result in the calculation performing the equation with the remaining actual values with tags with good quality and overriding the values for the tags that are bad quality.

•      Hold Sources To Last Good Value: When the data sources quality changes to bad quality the last good value will be used as the data source.  With Calculations that have multiple tag parameters as a source each individual tag value in the calculation will be held with its last good value when its individual data quality is bad.  This will result in the calculation performing the equation with remaining actual values with tags with good quality and overriding the values for the tags that are bad quality with each individual tags last good quality.

•      Set Sources To Tag Value: When the data sources quality is bad the value from another OPCSystems.NET Tag will be used.  With Calculations that have multiple tag parameters as a source each individual tag value in the calculation will be set from the other Tag value.  This will result in the calculation performing the equation with remaining actual values with tags with good quality and overriding the values for the tags that are bad quality with the assigned tag’s value.