Abstract: Combining the pault diagnosis technique and the embedded technology, a protable fault diagnosis instrument was developed for the miniature application. Its hardware configuration, dual CPU in special, and software structure, including the communication software, were described. The developed portable fault diagnosis instrument based on the dual CPU incorporates many functions, including the data acquisition, storage, and analysis as well as communication in a unit with low cost, can be widely used in the system monitor and diagnosis in various equipments and installations. The experiment results showed that its function is stable.

Key words: technology of instrument and meter, dual CPU, portable instrument of fault diagnosis, digital signal processor(DSP), singlechip macchine(SCM)