Arc light protection device and communication connection method between plug-ins of arc light protection device

The invention belongs to the field of bus arc light protection, and particularly relates to an arc light protection device and a communication connection method between plug-ins of the arc light protection device. According to the invention, through setting the unique corresponding relation among the slot, the level, the ID number and the MAC address, the actual slot positions of the arc light acquisition plug-in and the CPU plug-in are converted into the unique identity of the Ethernet MAC layer, and the corresponding communication configuration file and the specific sampling data file which are mutually sent are matched; a communication function of data interaction between the arc light acquisition board card and the CPU plug-in based on an Ethernet MAC layer in a configuration-free, setting-free and auto-negotiation mode is realized; in engineering application, the arc light protection device can realize a data exchange function between two types of plug-ins without downloading a communication configuratio