Sources available to a slave Axis for electronic gearing & camming

Enumerator:
RSIAxisMasterTypeMOTOR_FEEDBACK_PRIMARY  Use primary motor encoder from master.
RSIAxisMasterTypeMOTOR_FEEDBACK_SECONDARY  Use secondary motor encoder from master.
RSIAxisMasterTypeAXIS_COMMANDED_POSITION  Use command position from master.
RSIAxisMasterTypeAXIS_ACTUAL_POSITION  Use actual position from master.