Analog outputs are cross-referenced to the .Oper.ctlVal attribute of the protection relay's object class INC, controllable integer. If the INC object is readable, the .stVal attribute of the object is mapped to DNP3 AI data.
The protection relay platform contains a few controllable analog objects, for example, parameter setting group selection, tap changer control and fault record read selection. All analog objects are of integer type. The values do not have to be scaled.
The Analog Output Block DNP3 object group (41) is used for writing to a DNP3 analog output. Analog output can be also read from the protection relay, as object group 40. Reading an analog output returns the last written value to the object.
Class events are generated for changed Analog Output values. The DNP3 Analog Output event buffer size is 100.