Moxa Technologies A50 User manual

A50/A51/A60
Dec. 1999 ( 2nd Edition )
All Rights Reserved

Part I -A50/A51 RS-232 to RS-422/RS-485 Converter
A50/A51
RS-232 to RS-422/RS-485
Bidirectional Converter

Part II -A60 RS-232 Surge Protection
A60
RS-232 Surge Protection
Converter

A50/51/60User’sManual
The product described in this manual is furnished under a license agreement and may be
used only in accordance with the terms of the agreements.
Copyright Notice
Copyright 1999 Moxa Technologies Co., Ltd.
All rights reserved.
Reproduction in any form without permission is prohibited.
Trademarks
MOXA is a registered trademark of Moxa Technologies Co., Ltd.
All other trademarks or registered marks in this manual belong to their respective manufacturers.
Disclaimer
Information in this document is subject to change without notice and does not represent a commitment on
the part of Moxa.
Moxa provides this document “as is”, without warranty of any kind, either expressed or implied,
including, but not limited to, the particular purpose. Moxa may make improvements and/or changes in
this manual or in the product(s) and/or the program(s) described in this manual at any time.
Information provided in this manual is intended to be accurate andreliable. However, Moxa Technologies
assumes no responsibility for its use, or for any infringements of rights of the fourth parties which may
result from its use.
This product could include technical or typographical errors. Changes are periodically made to the
information herein; these changes may be incorporated in new editions of the publication.

MOXAInternetServices
Customer’s satisfaction is always our number one concern. To ensure that customers get the full benefit
of our services, Moxa Internet Services have been built for technical support, product inquiry, new driver
update, user’s manual update, etc.
The followings are the services we provide.
E-mail for technical support
address:[email protected]
FTP site for free driver update
address: ftp.moxa.com
or
ftp.moxa.com.tw
user ID: ftp
password: your_email_address
World Wide Web (WWW) Site for product info
address: www.moxa.com
or
www.moxa.com.tw

TableOfContents
Part I -A50/A51 RS-232 to RS-422/RS-485 Converter
Chapter 1. Introduction ………………………………………. 1
1.1 Overview 1
1.2 Features and Specifications 2
1.3 Package Check List 5
Chapter 2. Installation ……………………………………….. 7
2.1 Installation Procedure 7
2.2 Switch Function Description 7
2.3 LED Indicators 8
2.4 RS-422/RS-485 Pinouts 9
Chapter 3. Operation ………………………………………… 11
3.1 Point-to-point 12
3.2 Multidrop 14
3.3 Simplex/Transmit, Receive 17
3.4 Self Test 19
Appendix A RS-232 Pinouts and Cable Wiring ……………….. 21
Appendix B Impedance Matching and Termination Resistors…… 25
Appendix C Troubleshooting …………………………………. 27

TableOfContents
Part II -A60 RS-232 Surge Protection
Chapter 1. Introduction…………………………………………… 29
1.1 Overview 30
1.2 Features and Specifications 30
1.3 Package Check List 31
Chapter 2. Installation……………………………………………… 33
2.1 Installation Procedure 33
2.2 LED Indicators 34
2.3 Self Test 36
Appendix A RS-232 Pinouts and Cable Wiring…………………… 37
Appendix B Troubleshooting ……………………………………….. 41

11-1
1
1
1 Introduction
Overview
The MOXA RS-232 to RS-422/RS-485 bidirectional converters, A50 and A51, are
designed to convert unbalanced (single-ended) RS-232 signals to balanced
(differential) RS-422/RS-485 signals, and vice versa. They are the best choices for
those who want to control devices at longer distance and/or to communicate with
several devices via merely one link, particularly in the industry area. Point-to-point,
multidrop and simplex operations are available for most users' needs.
Outlook of A50
RS-422/485
RJ-45 Connector
Power Jack
RS-232
RJ-45 Connector

1-2
Outlook of A51
Features and Specifications
Features
Both A50 and A51 are RS-232 to RS-422/RS-485 bidirectional converters except
that A51 has one more feature: isolation protection, which provides high voltage
protection up to 2000V.
All the switches, SW1 and SW2, of A50/A51 are designed to be inside of the
converter to protect switch settings from unintended change and introducing
communication error without any warning. Hence, it is necessary to take the two
screws off and open the cover up if you need to change the operation mode via
sliding the switches.
The A50/A51 must be powered either from a DC +9V to +30V,
150mA power adapter or the pin 6 andpin 7 of the Terminal Block.
LED indicators are provided to show the status of data transmitting/receiving, RTS
signal and Power.
To avoid over-current from the remote ground to converter's ground, an protect
resistor has been added inside the A50/A51.
Specifications
vPower Supply -DC +9V to +30V, 150mA
vData Rate -Up to 921600 bps under 500 ft (0.15 Km)
vDistance -Up to 4000 ft (1.2 Km) under 115200 bps
vRS-232 RJ-45 Connector -
Supports TxD, RxD, DTR, DSR, RTS, CTS, DCD, GND
vRS-422/RS-485 RJ-45 Connector -
RS-422/485
RJ-45 Connector
Power Jack
RS-232
RJ-45 Connector