CAN(Controller Area Network) is a serial communication protocol with a very high level of security. It especially suits to distributed real-time system control and monitor, such as industrial machine control, aircraft engines, factory automation, medical equipment, building automation, remote data acquisition and control, environment monitor…etc. In order to use high performance CAN bus with I-8000 series main control unit of ICP DAS, we also provide the I-8120 library for I-8000 series main control unit after I-8120 drivers for WinCon and LinCon had been given. This library can help users not only to build their CAN system on the platform of I-8000 series main control unit, but also to structure a CAN network with ICP DAS CAN-related products and the CAN products from other companies. The general application architecture is depicted as the following figure :