ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / Power supply is the most critical unit in an airplane. A defect in a power supply might lead to a crash. Therefore, it is very useful and important to monitor the status of the airplane's power supply during flight. This paper presents a real-time evaluation system constructed by a central process unit for processing and detecting defects and several remote units for acquiring parameters. Because of the huge amount of data acquired, a combination of Ethernet and time division multiplexing technique has been applied for constructing a 2.5Gbps synchronous data transportation network for the system.