Design and Application of Communication Module in Intelligent Temperature Transmitter Based on Freemodbus

Freemodbus is an open source free Modbus protocol stack written by Austrians, and is widely used in embedded system field to realize the Modbus protocol. This article takes MSP430F149 MCU(Microcontroller Unit) as the control center. The MCU collects the raw sensor signals and converts it to digital temperature signals. Freemodbus works on the MCU, and communicates with a Modbus master station via RS485 to achieve the goal of intelligent temperature transmitter communication module. The test result shows that the communication module operates steadily, communicates reliably, and this project has certain practicability and popularization value.