RS422

RS-422 and RS-485 Application Note B&B Electronics Mfg. Co. Inc. P.O. Box 1040 -- Ottawa, IL 61350 PH (815) 433-5100 -- FAX (815) 434-7094 Internet Addresses: B&B Home Page: http://www.bb-elec.com Customer Service: sales@bb-elec.com Technical Support: techsupt@bb-elec.com © B&B Electronics - Revised October 1997 RS-422/485 Application Note B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350 PH (815) 433-5100 -- FAX (815) 434-7094 Cover Page Table of Contents CHAPTER 1: OVERVIEW ........................................................................... 1 INTRODUCTION ............................................................................................. 1 DATA TRANSMISSION SIGNALS ...................................................................... 1 Unbalanced Line Drivers ......................................................................... 1 Balanced Line Drivers ............................................................................. 1 Balanced Line Receivers.......................................................................... 3 EIA STANDARD RS-422 DATA TRANSMISSION .............................................. 3 EIA STANDARD RS-485 DATA TRANSMISSION .............................................. 6 TRISTATE CONTROL OF AN RS-485 DEVICE USING RTS.................................. 9 SEND DATA CONTROL OF AN RS-485 DEVICE .............................................. 11 CHAPTER 2: SYSTEM CONFIGURATION ............................................ 13...