At present, the power user electric energy data acquisition terminal function detection by manual inserting the RS-232 port, a detecting device and a terminal local communications, although it is mature and reliable, but there exists the problem of low detection efficiency and difficult to realize automation etc.. Therefore, this paper extends the acquisition terminal RS-485 meter auxiliary terminal function, to realize RS-485 meter reading for the acquisition terminal local communication port, open the RS-485 auxiliary terminal local communication and parameter setting function scheme. The study resolves currently restricting the acquisition terminal communication hardware port connection and realize automation technology bottleneck, the local communication and therefore, has the important breakthrough, but also to promote the realization of automated detection system of the collection terminal type and application provides a reliable solution.