Black Box IC050C User Manual

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MARCH 2000

IC050C
IC171C

RS422/485 Serial Interface Plus

RS422/485 SERIAL INTERFACE PLUS

FEDERAL COMMUNICATIONS COMMISSION

AND

INDUSTRY CANADA

RADIO FREQUENCY INTERFERENCE STATEMENTS

This equipment generates, uses, and can radiate radio frequency energy
and if not installed and used properly, that is, in strict accordance with the
manufacturer’s instructions, may cause interference to radio communication.
It has been tested and found to comply with the limits for a Class A
computing device in accordance with the specifications in Subpart J of Part 15
of FCC rules, which are designed to provide reasonable protection against
such interference when the equipment is operated in a commercial
environment. Operation of this equipment in a residential area is likely to
cause interference, in which case the user at his own expense will be required
to take whatever measures may be necessary to correct the interference.

Changes or modifications not expressly approved by the party responsible
for compliance could void the user’s authority to operate the equipment.

This digital apparatus does not exceed the Class A limits for radio noise emission from
digital apparatus set out in the Radio Interference Regulation of Industry Canada

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

TRADEMARKS USED IN THIS MANUAL

UNIX is a registered trademark of UNIX System Laboratories, Inc.

IBM and OS/2 are registered trademarks of, and PC/XT is a trademark
of IBM Corporation.

Microsoft is a registered trademark of, and Windows and Windows NT
are trademarks of Microsoft Corporation.

RS422/485 SERIAL INTERFACE PLUS

NORMAS OFICIALES MEXICANAS (NOM)

ELECTRICAL SAFETY STATEMENT

INSTRUCCIONES DE SEGURIDAD

1. Todas las instrucciones de seguridad y operación deberán ser leídas antes
de que el aparato eléctrico sea operado.

2. Las instrucciones de seguridad y operación deberán ser guardadas para
referencia futura.

3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de
operación deben ser respetadas.

4. Todas las instrucciones de operación y uso deben ser seguidas.

5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo,
cerca de la tina de baño, lavabo, sótano mojado o cerca de una alberca,
etc..

6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales
que sean recomendados por el fabricante.

7. El parato eléctrico debe ser montado a la pared o al techo sólo como sea
recomendado por el fabricante.

8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más
allá a lo descrito en las instrucciones de operación. Todo otro servicio
deberá ser referido a personal de servicio calificado.

9. El aparato eléctrico debe ser situado de tal manera que su posición no
interfiera su uso. La colocación del aparato eléctrico sobre una cama,
sofá, alfombra o superficie similar puede bloquea la ventilación, no se
debe colocar en libreros o gabinetes que impidan el flujo de aire por los
orificios de ventilación.

10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de
calor como radiadores, registros de calor, estufas u otros aparatos
(incluyendo amplificadores) que producen calor.

RS422/485 SERIAL INTERFACE PLUS

11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo
del tipo descrito en el instructivo de operación, o como se indique en el
aparato.

12. Precaución debe ser tomada de tal manera que la tierra fisica y la
polarización del equipo no sea eliminada.

13. Los cables de la fuente de poder deben ser guiados de tal manera que no
sean pisados ni pellizcados por objetos colocados sobre o contra ellos,
poniendo particular atención a los contactos y receptáculos donde salen
del aparato.

14. El equio eléctrico debe ser limpiado únicamente de acuerdo a las
recomendaciones del fabricante.

15. En caso de existir, una antena externa deberá ser localizada lejos de las
lineas de energia.

16. El cable de corriente deberá ser desconectado del cuando el equipo no
sea usado por un largo periodo de tiempo.

17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean
derramados sobre la cubierta u orificios de ventilación.

18. Servicio por personal calificado deberá ser provisto cuando:

A: El cable de poder o el contacto ha sido dañado; u

B: Objectos han caído o líquido ha sido derramado dentro del

aparato; o

C: El aparato ha sido expuesto a la lluvia; o

D: El aparato parece no operar normalmente o muestra un cambio en su

desempeño; o

E: El aparato ha sido tirado o su cubierta ha sido dañada.

RS422/485 SERIAL INTERFACE PLUS

Contents

Chapter Page

1. Specifications....................................................................................................1

2. Introduction .....................................................................................................2

2.1 Overview..................................................................................................2

2.2 What’s Included......................................................................................2

2.3 Features...................................................................................................3

2.4 Technical Description............................................................................3

3. Address Selection.............................................................................................6

4. Option Selection ..............................................................................................8

5. Installation......................................................................................................15

5.1 Software Installation .............................................................................15

5.1.1 Windows 3.1x...............................................................................15

5.1.2 Windows 95/98 ..........................................................................15

5.1.3 Windows 98..................................................................................15

5.2 Hardware Installation ...........................................................................15

6. Windows 3.1 Installation................................................................................16

7. Troubleshooting ............................................................................................19

Appendix: Circuit-Board Design.......................................................................23

1

CHAPTER 1: Specifications

Number of Ports — Single RS-485/422

Speed — IC050C: 115.2 Kbps; IC171C: 460.8 kbps and higher

RS-485 Operation — 2- or 4-wire

Connectors — DB25P

Maximum Distance — Up to 5000 ft. (1524 m)

Communications Chip — IC050C: 16550 UART; IC171C: 16950 UART

MTBF — >150,000 hours

MTTR — <0.25 hours

Materials — Boards are solder mask over bare copper or tin nickel

Operating Temperature — 32° to 122°F (0° to 50°C)

Storage Temperature — -4° to 158°F (-20° to 70°C)

Humidity — 0 to 90% relative humidity, noncondensing

Power — +5 VDC @ 160 mA

1. Specifications

2

RS422/485 SERIAL INTERFACE PLUS

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.ME|MORE [ENTER] or B:TYPE
READ.ME|MORE [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

2. Introduction

3

CHAPTER 2: Introduction

2.3 Features

Listed below are the special features your Serial Interface Plus offers.

• Single-channel RS-485/422 adapter for Windows, OS/2, Windows NT,
and DOS communications.

• Addressable as COM1: through COM4: or twelve other pre-selected
address options.

• Automatic RS-485 protocol control allows card to appear to be RS-232;
therefore, no special drivers or additional software is required.

• “PAL” allows for unique OEM address selection.

• Individually selectable addresses and extended AT interrupts allow
for seamless integration into OS/2 and Windows systems.

• IRQs 2–7, 10–12, and 15 supported.

• IRQs can be shared or individually set for each port.

• 16-bit address decode allows for easy integration.

• Selectable termination, echo mode, and two- and four-wire operation.

2.4 Technical Description

The RS422/485 Serial Interface Plus (IC050C) provides one RS-422/485
serial port utilizing the 16550 UART. This chip features programmable baud
rate, data format, and interrupt control, and a 16-byte input and output FIFO.
The IC171C uses a 16950 UART, and has a 128-byte FIFO.

RS-422

RS-422, unlike RS-232, is a differential interface that defines voltage levels,
and driver/receiver electrical specifications. On a differential interface, logic
levels are defined by the difference in voltage between a pair of outputs or
inputs. In contrast, a single-ended interface, for example RS-232, defines the
logic levels as the difference in voltage between a single signal and a common
ground connection. Differential interfaces are typically more immune to
noise or voltage spikes that may occur on the communication lines.
Differential interfaces also have greater drive capabilities that allow for longer
cable lengths. RS-422 is rated up to 10 Mbps and can have cabling 5000 feet
(1524 m) long. RS-422 also defines driver and receiver electrical
characteristics that will allow 1 driver and up to 32 receivers on the line at
once. RS-422 signal levels range from 0 to +5 volts. RS-422 does not define

a physical connector.

4

RS422/485 SERIAL INTERFACE PLUS

RS-530 and RS-449

RS-530 and RS-449 (EIA-530 and EIA-449) are similar to RS-422 and
RS-485 in the fact that they are differential interfaces, but these two standards
provide a specified pin-out that defines a full set of modem control signals
that can be used for regulating flow control and line status. RS-449 is defined
on a standard 37-pin D sub-connector, while RS-530 is backward-compatible
and is replacing RS-449. RS-530 is defined on a 25-pin D sub-connector.

Figure 2-1. RS-422/530 Connection.

RS-485

This interface is very similar to RS-422 is several ways. RS-485 is a differential
interface that allows cable lengths up to 5000 feet (1524 m) and data rates up
to 10 Mbps. The signal levels for RS-485 are the same as those defined by RS-

422. RS-485 has electrical characteristics that allow for
32 drivers and 32 receivers to be connected to one line.

TX+
TX­RX+
RX-

RX+
RX­TX+
TX-