Specifications

Chapter 1 - Overview RS-422 And RS-485 Applications Ebook
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Overview
The purpose of this ebook is to describe the main elements of RS-422
and RS-485 data communications systems. The authors have
attempted to cover enough technical details so that personnel will have
the necessary information to be successful in designing, modifying or
troubleshooting an RS-422 or RS-485 data communication system.
Since both RS-422 and RS-485 are data transmission systems that use
balanced differential signals, it is appropriate to discuss both systems
in the same publication. Throughout this document the generic terms
of RS-422 and RS-485 are used when referring to equipment and
systems based on the EIA/TIA-422 and EIA/TIA-485 Standards.
1 In This Chapter
Assumptions ................................................................................................. 6
What is RS-422/RS-485? ............................................................................... 6
Data Transmission Signals ............................................................................. 8
RS-422 and RS-485 Terminals and Designations ........................................... 13
Common Mode Voltage ............................................................................... 14
Tri-State Control ......................................................................................... 16
CHAPTER 1