Save process values (PV) as historical data

For attribute data to be stored in the historian, a host AppEngine must be configured to send history data to a Historian node. For each object, you can configure attributes of the following data types to be saved to the Historian.

• Float (numerical).

• Double (numerical) maps to a Historian float data type. If the value of the double exceeds the range of a float, its value is clamped to the maximum value for the float and the quality is set to Uncertain.

• Integer (numerical)

• Boolean (non-numerical)

• String – Unicode (non-numerical). Limited to 512 characters. Characters that exceed the 512 maximum length are truncated. If truncation occurs, the quality value of the packet is set to Uncertain.

• CustomEnum (non-numerical) maps to a Historian integer.

• ElapsedTime (numerical) maps to a Historian float and is converted to seconds.

• Arrays or parts of arrays are not supported.

• Enum type attributes are saved as Historian integer ordinal values.

• IEEE NaN values for float and double data types are converted to null values prior to being sent to the historian. NaN values are associated with a Bad OPC data quality.

• All numerical attributes sent to the Historian are in the engineering units specified for the attribute. The Historian does not scale numerical values.