In this paper, an Ethernet data acquisition and transmission unit designed for general purpose information exchange between different channels has been proposed. In hardware, it is composed of only one chip and multiple interfaces which result to easy design and excellent stability; in software, the μC/OS-II, an embedded Real Time Operation System(RTOS), is applied and runs on the microcontroller, and a configuration software used to configure all of the unit parameters by TCP connection runs on the computer. Because of the RAM size and other resources limitation, we improved the μC/OS-II in several aspects. The results of performance evaluations show that the improved μC/OS-II uses less RAM space, more data are exchanged between the Ethernet and other interfaces, and the time of data waiting for processing is ensured and satisfying.