RS422/485 SERIAL INTERFACE PLUS
2. Introduction
2.1 Overview
The RS422/485 Serial Interface Plus is an easy-to-use RS-485 interface for your PC. It incorporates unique hardware circuitry that enables the RS-485 interface to appear to be an RS-232 interface, requiring no additional software drivers.
Previous RS-485 interfaces required the software to “turn on” RTS to transmit and then “turn off” RTS at the end of the character. This required overhead and special interrupt processing. Newer operating systems such as Windows™, Windows NT™, OS/2®, and other multi-tasking operating systems typically will not allow the user access to the low-level registers of the UART chip without writing a specialized driver. Since the RS422/485 Serial Interface Plus emulates an RS-232 port, installation is as easy as picking an address and interrupt level.
The README file on the serial utility disk contains information about the latest changes and revisions. To view this file, insert the diskette into drive A or B and type A:TYPE READ.MEMORE [ENTER] or B:TYPE READ.MEMORE [ENTER].
2.2 What’s Included
Your Serial Interface Plus should come with the following items. If any of these items are missing or damaged, contact Black Box.
(1)RS422/485 Serial Interface Plus card
(2)3.5" serial utility diskettes
This manual
