Implementation of Serial Communication between PC and DSP Processor Using Modbus Protocol

This paper described the principle, application and implementation of serial communication between PC and a Digital Signal Processor (DSP). The TMS320F28031 which is a type of DSPs made by Texas Instruments (TI) is used in this implementation. This DSP processor has serial communication interface (SCI) module for serial communication. The SCI is a two−wire asynchronous serial port, commonly known as a UART (Universal Asynchronous Receiver/Transmitter). The standard of Modbus protocol is implemented for this serial communication. The Modbus protocol provides an industrial standard method that Modbus devices use for parsing messages. PC (Personal Computer) can read/write one or more registers of DSP processor using Modbus communication. This paper highlights the basics of Modbus protocol and also explains the software detail of Modbus implementation.