Hexin Technology HXSP-422A User Manual

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HXSP-422 RS-232/RS-422 Converter

User Guide

Product introduction

HXSP-422 series converter is bi-directional connector converter between
RS-232 and RS-422; it is mainly used for communication between main
controller machines, main controller machine and SCMs or Peripherals,
point to point and point to points remote communicate network, it achieve
request-response communication between multi-machines, it is mainly
used for the field of electricity, industrial automatic control, IC card billing
system; such as one card solution, access control system, parking
system, and so on.
HXSP-422 series converters change the TXD and RXD signals of RS -232
serial port to 4 wire full duplex RS-422 signal. No need to get through the
power, it can get the electricity from the 3rd pin of RS-232 interface , at
the same time, there is a request sending by 7th pin(RTS), 4th pin data
terminal prepares(DTR) to help power supplying HXSP-422. The
automatically process control make you need not reset and make a easy
application of the hardware and software installation.

Specification

1. Standard: Accord EIA RS-232, RS-422 standard.

2. Connector: DB9 female on RS-232 side, DB9 male with 6 terminal
block on RS-422 side.

3. Work methods: asynchronous, point to point or multi -point, 4 wire
full-duplex.

4. Transmission medium : Ordinary Line , twisted pair cable or Shielded
Wire

5. Baud rate: 300~115000bps.

6. Transmission distance: 5 meters (RS-232 side) and 1200 meters
(RS-422 side).

7. Communication protocol: Transparent.

8. Environment: -10℃ to 85℃ working temperature, 5% to 95% relative

humidity.

9. Signals: RS-232(TXD, RXD,GND); RS-422(TX+,TX-,RX+,RX-,GND).

10. Support 600W surge protection, 15KV static protection.

Connection wire and signals ：

RS-232 Side(DB9 Female) RS-422（ DB9 Male ）

1

. . . .

9

1

. . . .

9

RS-232 pin definition

DB9 Fema le

1234567

8

DCD

RXD

TXD

DTR

GND

DSR

RTS

CTS

RS-422 pin definition

DB9 Male

12345

6

T+T-R+R-GND

+12V

There are two situations about working power supply:

1. It can get the electricity from the 3rd pin of RS -232 connector, at the same

time, there is a request sending by 7th pin (RTS), 4th pin data terminal
prepares (DTR) to help power supplying HXSP -422.

2. When the RS-232 cannot power supply, it can be power supply by RS -422

6th pin (+5~+12V) and 5thPin (GND).

Installation and Application

1. Installation:

① Prepare four pieces ordinary wire or two pair twisted-pair cable before
installing HXSP-422 products;

② Close the serial port of equipment (turn off the equipment);
③ The RS-232 port of HXSP-422 series converter use DCE method, it can

plug into DB9 Male DTE equipment directly (e.g. COM port of
computer) ,and get the electricity from TXD 、DTR、RTS signals but please
notice that the SL (signal level) should be higher than +5V，if the equipment
uses the DCE method, it must be connect as below:

Equipment

DB 9-pin corresponding

RS-232 of HXSP-422

123456789

DB9 male of DCE

132456789

RS-422 Equipment and HXSP-422 connection table:
HXSP-422 RS-422

Board

RS-422 equipment

TX+

RX+
TX-

RX­RX+

TX+
RX-

TX­GND

GND
+12V

2. Application

1) The communication of RS-232 equipment and RS-422 equipment
This method is mainly used for control -side equipment connector is RS -232c ,
and the connector of equipment under control is RS-422 ,The two side can not
communicate directly because of disaccord of two side electrical specialty ,
HXSP-422 series converter can be used for transparent change the RS-232
signals to RS-422 signals.

2) RS-422 Network Application
A RS-232 Host will control more tha n 32 units RS-422 equipment, use this
method, in order to avoid signal reflex and interfering signal, it should be add
the matched resistance on the terminal circuit ( 120Ω, 1/4 w)

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RS-422 Network Bus

Connection schematic diagram

Problem analysis：

1. Data communication unsuccessful

A. Check RS-232 interfaces whether to be correct;
B. Check RS-422 interfaces whether to be correct;
C. Check whether RS-232 signal level（TXD、DTR、RTS） lower than＋5V, if that,
it can get through power from 6th pin of DB9 Male.

2. Data missing or messy code

A. Check whether the baud rate and format of both sides of data communication
equipment are same.
B. If possible, add the matched resistance on the terminal circuit (120 Ω,1/4 w)