Design considerations of a serial communications system for adjustable frequency drives

The author describes the design of a simple and effective serial communications system for adjustable frequency drives. It is designed to provide the attributes of simplicity, flexibility, and room for future expansion. A network of three AC adjustable frequency drives has been set up and tested with a menu-driven user-friendly program which has been developed to run under the MS-DOS environment. Based on the results from the tests performed on the terminal and network software, the communications system designed for the AC drives has proven to be successful with respect to both man-machine and machine-machine interfaces.<>