Abstract:In order to get methods of accurately obtaining machine tools condition monitoring signals, the three schemes of obtaining machine tools condition signals were researched, which included external setting sensor signals, internal setting sensor signals and servo drivers monitoring interface signals. The three signals were all reliable signal sources, however, the quality and difficulty level to obtain of signals were different. These three schemes were compared and analyzed. The analysis result has reference significance for researching the monitoring technology on-line of CNC machine tools servo feed system and improving reliability and machining quality of machine tools.