Design and Implementation of Intelligent Acquisition Terminal Based on Modbus

With the continuous development of social economy, intelligent acquisition terminal plays an important role in some remote and abusive environments. In this paper, an intelligent integrated acquisition terminal is proposed, which can be effectively applied to irrigation area information collection, earthquake disaster monitoring and other scenarios. The acquisition terminal (RTU) proposed in this paper adopts a design scheme combining GD32F407 embedded system and embedded industrial computer to complete data collection, processing, transmission, display, storage and intelligent control of equipment. The RTU acquisition base plate is designed by GD32F407 chip, including RS485, 4-20MA, SSI Gray code, relay control, Ethernet and other interfaces [1]. The RS485 interface uses Modbus Rtu protocol to request data from sensors connected to the outside. SSI Gray code interface can be connected to absolute value encoder to collect data, gray code interface carries on data transmission through 422 interface on hardware, and carries on data latching at corresponding edge through analog clock signal on software level. Modbus TCP protocol is used to exchange information between the acquisition baseboard and the industrial computer through Ethernet. The industrial computer runs the fast control configuration software, which can receive the transmitted data and realize intelligent control of external devices.