An Embedded Modbus Compliant Interactive Operator Interface for a Variable Frequency Drive Using Rs 485

Abstract

The paper proposes the architecture and software design of a Modbus Compliant Operator Interface Panel (MCOIP) for a high speed Variable Frequency Drive (VFD)-a state of the art embedded design that offers several key advantages over the existing proprietary industrial models in use today. The use of serial Modbus RTU communication over RS485 allows an economically feasible, open source, vendor neutral, feature laden, robust and safe operating model. Through the use of an ARM based RISC microcontroller, the low response time of the design makes the human machine interface more real-time and interactive.