Most large monitoring systems not only can monitor the main equipment but also can integrate power and environment monitoring. So it chooses popular Modbus communication protocol inorder to be compatible with more devices. But most brands of UPS power communication have their own packaging formats,so providing RS232, RS422 or Network port cannot satisfy such monitoring system.We need protocol conversion actor- Modbus protocol converter. It is a kind of intelligent protocol converter,which is developed according to centralized monitoring in the current market.