Determines the active source for the Electrical Study. Possible values for this property are -1: None (default), 0: Active Source, 1: SCADA, 2: Operator, 3: Control Center, 4: Billing, 5: Calculated, or 6: Database. The selected source type must exist in the Measurement to be set as an Electrical Study input. If this property is set to 0 (ActiveSource), it follows the configuration performed in the ActiveSource property. It is not possible to select type 0 (ActiveSource) if the ActiveSource property is set to 100, 101, 102, 103, 104, 105, or 106 (Electrical Study outputs). In case the selected source is deleted, this property assumes a value of -1 (None).