Brainboxes PCI Velocity RS422 User manual

422

Guarantee.
FULL 36 MONTHS GUARANTEE.
BRAIN BOXES guarantee your Serial Port Card for a full 36
months from purchase, parts and labour, provided it has been used
in the specified manner. In the unlikely event of failure return your
interface to BRAIN BOXES or to your Dealer, with proof of
purchase, who will determine whether to repair or replace this
product with an equivalent unit.
COPYRIGHT.
COPYRIGHT © 1985-1997 BRAIN BOXES.
All rights reserved. No part of this hardware, circuitry or manual
may be duplicated, copied, transmitted or reproduced in any way
without the prior written consent of BRAIN BOXES.
Serial Solutions are designed, manufactured, and supported by
BRAIN BOXES.
Unit 3F, Wavertree Boulevard South,
Wavertree Technology Park,
Liverpool, L7 9PF,
England.
Telephone: [phone]
Fax: [phone]
E-mail: help@brain_boxes.cybase.co.uk
Web: www.connect.org.uk/merseymall/brain_boxes/
ACKNOWLEDGEMENTS.
BRAIN BOXES is a trademark of BRAIN BOXES.
IBM, Commodore, COMPAQ, Olivetti, AMSTRAD, Hewlett
Packard, H.P. and EPSON are trademarks of the relevant
companies. OS/2 and Microchannel Architecture are trademarks of
IBM. Windows is a trademark of Microsoft.

AT & OPTO DUAL RS422/485 Introduction
Intro 1
AT DUAL RS422/485 MANUAL
Outline Contents
Chapter 1. Optional Serial Solution Software
Chapter 2. Opto and AT Dual RS422/485 hardware
configuration
Chapter 3. How to install your card into the PC
Chapter 4. Opto and AT Dual RS422/485 software
configuration
Chapter 5. Serial Utility disk and Programming
guide.
THE LAYOUT OF THIS MANUAL
Chapter 1 - Serial Solution Software, is an overview of
the optional companion software package that is the ideal
companion for our range of serial port cards. Buy it from
your dealer now!
Chapter 2 - Opto and AT Dual RS422/485 Hardware
Configuration, shows you how to configure the settings
of the Opto and AT Dual RS422/485 cards, after a brief
discussion of the RS232, RS422 and RS485 standard,
serial port IRQ and address selection, RS485 gating and
multiplexing and sample wiring diagrams are given.

Introduction AT & OPTO DUAL RS422/485
Intro 2
Chapter 3 - How to install your card into the PC, After
configuration a step by step guide on how to open your
PC and insert the card.
Chapter 4 - Opto and AT Dual RS422/485 Software
Configuration, details on how to install your Opto and
AT Dual RS422/485 in DOS, Windows 3.x, 95 and NT as
well as OS/2.x and OS/2 Warp.
Chapter 5 - Serial Utility Disk and Programming
Guide, describes the sample programs on the disk
supplied with the card. The chapter concludes with a
detailed discussion of how to program the 16450 serial
port chip.
The index - covers the complete contents of this manual.

AT & OPTO DUAL RS422/485 Introduction
Intro 3
Index
CHAPTER 1................................................................. 1
Introduction.............................................................................. 1
Introducing Serial Solution Software......................................... 1
Serial Solutions For DOS.......................................................... 2
Serial Solutions For Windows 3.x.............................................. 3
Serial Solutions For Windows 95 .............................................. 4
The Comtest.exe Program......................................................... 4
Complete Documentation and Technical Backup....................... 4
CHAPTER 2................................................................. 5
Introduction.............................................................................. 5
AT Dual Port RS422/485 Card Features. .................................. 5
The RS232 Standard................................................................. 7
The RS422 Standard................................................................. 7
The RS485 Standard................................................................. 8
Terminating Impedance’s. ......................................................... 9
Fail Safe Open Circuit Detection. .............................................. 9
Fail Safe Short Circuit Protection.............................................. 9
Configuring The RS422 Card.................................................. 11
Serial Port Jumpers. ............................................................... 12
Serial Port Address Selection.................................................. 13
Serial Port IRQ Interrupt Jumper Selection. ............................ 13
Serial Port 485 Gating Jumper Block....................................... 16
Serial Port Multiplex Jumper Block......................................... 18
RS485 Operation. ................................................................... 21
OPTO Dual RS422/485 Optional Parallel Port ........................ 27
Optional Parallel Port Installation............................................ 28
CHAPTER 3............................................................... 29
Serial Card Installation............................................................ 29
Problems!................................................................................ 32

Introduction AT & OPTO DUAL RS422/485
Intro 4
CHAPTER 4............................................................... 33
Introduction............................................................................ 33
Informing The PC Of The Port Address................................... 33
Microsoft Windows Version 3.x.............................................. 36
Microsoft Windows 95............................................................ 39
Changing Port Settings in Windows 95.................................... 47
Microsoft Windows NT........................................................... 51
OS/2 Version 2.x and OS/2 Warp............................................ 54
CHAPTER 5............................................................... 55
Introduction............................................................................ 55
Utility Disk Contents............................................................... 55
ADDRCOM Program.............................................................. 56
ADDRLPT Program. .............................................................. 57
The COMTEST Program........................................................ 57
COMM.BAS - A Simple BASIC Comms Program.................. 58
BASIC's Serial Communications Support................................ 59
Handshake lines....................................................................... 60
Output Handshake Lines - DTR and RTS................................ 60
Input Handshake Lines CTS, DSR, DCD and RI..................... 60
RS232.BAS - Demonstrates Using Serial Port Chips............... 61
Serial Port Address.................................................................. 63
Baud Rate Selection................................................................ 63
Data Word Length, Parity and Stop Bit Selection.................... 64
Setting The RTS and DTR Output Handshake Lines. .............. 64
Reading The CTS, DSR & DCD Input Handshake Lines......... 65
Detecting Incoming Data......................................................... 65
Sending Outgoing Data........................................................... 66
PC Serial Port Chips................................................................ 67

AT & OPTO DUAL RS422/485 Serial Solutions Software
Chapter 1 Page 1
CHAPTER 1
SERIAL
SOLUTION
SOFTWARE.
Introduction
This chapter is a brief description of the OPTIONAL Serial
Solutions software package, this is purchased SEPARATELY and
is available from YOUR DEALER.
Introducing Serial Solution Software
The perfect partner for any Serial Port is Serial Solutions
Software! Serial Solutions is a fully featured suite of programs
designed to squeeze the most from PC serial communications.
Serial Solutions is made up of the following components:-
Serial Solutions for DOS
Serial Solutions for Windows 3.x
Serial Solutions for Windows 95
All the Serial Solutions drivers have the following features:-
Drivers for PC standard UARTs e.g. 8250 and 16450
a) Drivers for PC standard UARTs e.g. 8250 and 16450
b) Drivers for PC FIFO UARTs e.g. 16550 as well as the new
improved 32 byte 16650 and 64 byte 16750 UARTs.
c) Support for shared interrupt cards e.g. our Quad 232, Lynx
232 and Quad 422 cards.
d) Support for any mix of RS232, RS422 and RS485 handshake
schemes.
e) Support for wider range of Baud rates and for more than 4
serial ports.

Serial Solutions Software AT & OPTO DUAL RS422/485
Chapter 1 Page 2
Serial Solutions For DOS
Serial Solutions for DOS consists of the following
programs:-
NewCOM.sys A device driver, it supports COM1 to
COM16, allowing 16 serial ports to be used
under DOS. It also includes an interrupt
handler for enhanced performance with user
definable buffer sizes. Accessible from all DOS
languages. It is the heart of the Serial Solution.
It has extensive handshaking support,
implementing both hardware handshaking
using any combination of the DTR, DSR,
CTS, RTS, and DCD lines, and a software
handshake using the XON/XOFF protocol.
NewCOM24.sys A device driver providing support for 24
ports.
NewCOM32.sys A device driver providing support for 32
ports.
NewMode.exe A replacement for the DOS 'mode com...'
command. NewMode is used to set the serial
parameters, including the port address, IRQ
line used, the baud rate, parity and data and
stop bit options.
e.g. NEWMODE COM5:38400,E,7,1 01A0 7
Baud rates supported are from 110 baud to
115,200 baud! Included is a very handy query
mode that reports the settings of the various
serial ports. Flexible and fast!
EASY programs. The EASY disk contains short, simple to
understand and use EASYBAS, EASYC and
EASYPAS programs, providing straight
forward, file type i/o to serial ports with debug
information. Use these FIRST, base your

AT & OPTO DUAL RS422/485 Serial Solutions Software
Chapter 1 Page 3
sample applications on them.
Source code, make files and compiled ready to
run programs supplied.
TERM programs A suite of larger terminal emulation programs
written in C (Cterm), Assembly language
(Aterm), Pascal (Pasterm), BASIC (BASterm)
and FORTRAN (FORterm) show how to
access the NEWBIOS routines as well as the
simple file i/o to ports. They contain many
lines of code and are thus harder to grasp.
They demonstrate in depth serial port
programming in a variety of languages but
they are also useful tools for using serial
devices.
Serial Solutions For Windows 3.x
Serial Solutions for Windows 3.x works with Windows 3.0,
3.1 and 3.11 as well as Windows For Workgroups 3.11.
Serial Solutions for Windows 3.x consists of the following
programs:-
Setup.exe The install routine for the package.
Port.DLL Enhanced Control Panel applet. Allows
configuration of extra serial ports from the
Windows Control Panel. Supports single as well
as multiport cards using shared interrupts.
BbLynx.drv Replacement for COMM.DRV.
LynxAPI.dll Enhancement to the Windows Comms API's
allowing support for more than 9 ports.
Term.exe Terminal program.
EasyCWIN C source code, project files and ready to run
.exe program for an easy to understand
Windows terminal program. Learn how to write
Windows comms apps correctly the easy way.

Serial Solutions Software AT & OPTO DUAL RS422/485
Chapter 1 Page 4
Serial Solutions For Windows 95
Windows 95 has an improved communication API and
directly supports up to 255 ports. Our Windows 95 driver
supports the shared interrupt mechanism used on our multiport
cards. Serial Solutions for Windows 95 consists of the following
programs:-
Bbcommsp.inf The information file to aid the installation process
"Have Disk....”
Bbcommui.dll The DLL and..
BBcomm.vxd ..the virtual device driver providing the shared
interrupt handler and despatch routines.
The Comtest.exe Program
Comtest is a short but invaluable program that is used to
check that the serial port at a particular i/o address is functioning
correctly and is connected to the particular IRQ line. The program
correctly identifies the UART type e.g. non FIFO, 16550 FIFO,
16550AF FIFO and the improved 16650 32 byte FIFO and 16750
64 byte fifes. By employing the built in loop back capability of the
PC serial port chip, a full test of the baud rate generator,
transmitting and receiving buffer, parity enable and start stop bit is
performed. There is no need for a second serial port or a cable
when using this utility.
Complete Documentation and Technical Backup.
We believe in supplying complete documentation with every
package we sell. The Serial Solution Software Package is no
exception, it has an attractive manual in an A5 binder with slip case,
containing over 150 pages of in-depth technical detail with
comprehensive indexes and table of contents. We guarantee your
Serial Solution Software package for a full 12 months from
purchase. A complete technical backup service is available to
ensure that you get the maximum performance out of your
investment.

AT & OPTO DUAL RS422/485 Hardware Configuration
Chapter 2 Page 5
CHAPTER 2
AT DUAL PORT RS422/485
HARDWARE CONFIGURATION
Introduction.
This chapter explains how to configure and install the Serial
Solution AT Dual Port RS422/485 and Opto Isolated AT Dual
Port RS422/485 card in an IBM PC computer. Detailed
instructions are given how to set the address select & IRQ jumpers.
RS485 users may need to alter the 485 Gating and Multiplex
jumpers.
The half size RS422/RS485 cards will fit into long or short
slots, in standard 8 bit PC slots or in the longer 16 bit AT slots. The
card works in PC, XT, AT, 386 ,486 and Pentium PC compatibles.
AT Dual Port RS422/485 Card Features.
The AT Dual Port RS422/485 has the following features:-
• Two ports independently selectable as RS422 or RS485.
• Reliable communications up to 4000 feet, 1.2 Kilometre.
• 100% IBM Compatible serial port Texas Instruments 16C550
• Jumper selectable serial port address, COM1 -COM8.
• TXD, RXD, RTS and CTS signals.
• Two or Four wire operation.
• RS485 Gating jumper options:
TXD driver Gating: Always On or RTS enable.
RXD receiver Gating: Always On or RTS disable.
• RS485 TXD/RXD multiplex selectable by jumpers:- either
FULL DUPLEX or HALF DUPLEX.
• On board 120 Ohm terminating resistors.
• On board Fail Safe open circuit and short circuit detection.
• Fully double buffered for reliable asynchronous operation.
• High speed circuitry to ensure operation with fast PC's e.g.

Hardware Configuration AT & OPTO DUAL RS422/485
Chapter 2 Page 6
200Mhz Pentium Pro machines WITHOUT use of extra wait
states.
• Jumper selectable interrupt level. IRQ 2-7, 10-12 & 15.
• One Centronics Parallel printer port, 100% IBM compatible*
• Jumper Selectable Port address, LPT1 - LPT3*
*Available only on the OPTO ISOLATED AT Dual Port
RS422/485
Serial Port Features:-
Baud Rate: 50 Baud to 115,200 Baud.
Word Length: 5, 6, 7 or 8 bits.
Parity: Even, Odd, None, Mark or Space.
Start Bit: 1 start bit always sent.
Stop Bits: 1, (1.5 for 5 bit data word length) or 2.
Clock Input: 1.8432 MHz.
I/O Connection: Dual 9 pin D Male type connectors.
Drivers: SN75174
High Level Voltage: 3.7V typical at 33mA source
Low Level Voltage: 1.1V typical at 33mA source
High Level Current: -60mA max
Low Level Current: 60mA max
Receivers: SN75175
Difftial I/P threshold: 200mV max.
Hysteresis: 50mVolt typical
Input Impedance: >12K Ohm without terminators.
AT Dual Port RS422/485 Dimensions: 5.40 x 4.20 in
13.0 x 10.6 cm
Opto Isolated RS422/485 Dimensions: 5.40 x 4.20 in
13.8 x 10.6 cm
Opto RS422/485 Optical Isolation:-
DC Isolation: +/- 1500 Volts DC
AC Isolation: 1000 Volts AC

AT & OPTO DUAL RS422/485 Hardware Configuration
Chapter 2 Page 7
The RS232 Standard
The RS232 standard is ancient in computer industry terms.
It was introduced in 1962, and is now widely established
throughout the computer industry. It is a slow speed, short
distance, single ended transmission system (i.e. only one wire per
signal). Typically RS232 maximum cable length is 50 feet with a
maximum data rate of 20K bits per second. RS232 is for data
transmitted from 1 driver to 1 receiver.
RS232C Standard
1 Driver 1 Receiver
Line Length Max Data Rate
50 Feet = 15m 20 Kbits/sec
TTL
TTL
GROUND GROUND
DR
The RS422 Standard.
The RS422 standard defines a serial communications
standard. RS422 is a high speed and/or long distance data
transmission. Each signal is carried by a pair of wires and is thus a
differential data transmission system. Over distances up to 40 feet
the maximum data rate is 10 Megabits per second, and for distances
up to 4000 feet the maximum data rate is 100 Kilobytes per second.
A 120 Ohm resistor should be used to terminate the receiving end
of the line. It is generally used between one transmitter receiver pair
to ONLY one other transmitter receiver pair, but each output can
drive up to 10 receivers.

Hardware Configuration AT & OPTO DUAL RS422/485
Chapter 2 Page 8
RS422 Standard
1 Driver up to 10 Receivers
Line Length Max Data Rate
40 Feet = 12m 10 Mbits/sec
400 Feet = 122m 1 Mbits/sec
4000 Feet = 1219m 100 Kbits/sec
DR TTL TTL
The RS485 Standard.
The RS485 standard is similar to the RS422 standard upon
which it is based. The main difference is that up to 32 transmitter
receiver pairs may be present on the line at one time. A 120 Ohm
resistor should be used to terminate either end of the main line. If
more than one device may transmit data, the RTS line is used as
transmit enable signal, so preventing contention between talkers.
RS485 Standard
Up to 32 Driver/Receiver Pairs
Line Length Max Data Rate
40 Feet = 12m 10 Mbits/sec
400 Feet = 122m 1 Mbits/sec
4000 Feet = 1219m 100 Kbits/sec
DD
RR R

AT & OPTO DUAL RS422/485 Hardware Configuration
Chapter 2 Page 9
Terminating Impedance’s.
RS422 and RS485 lines should be terminated at the end of
the main branch of the RECEIVER, in the cables characteristic
impedance. These terminating impedance’s stop echoes caused by
the serial data being reflected back at the cable ends. It is not
necessary to terminate the transmitter end of the twisted pair.
The AT Dual Port RS422/485 card has the correct 120
Ohm terminating resistors for the RXD twisted pair line and the
CTS twisted pair line fitted on the RS422/485 card for both the
serial ports on the card.
There is no need to add any more at the PC end.
The terminating impedance’s shown later in the wiring
diagrams of Figure 2-7, Figure 2-8, Figure 2-10 & Figure 2-12 are
automatically provided by the on board resistors and do not have to
be added by the user.
Fail Safe Open Circuit Detection.
Open circuit is when there are no drivers on the circuit. This
occurs by design in party line multi driver/receiver systems and
unintentionally when the twisted pair line is accidentally cut or
disconnected or the transmitting device fails. In RS485 party line
systems there are extended periods of time when none of the many
possible talkers is gated onto the bus. This is known as the line idle
state and occurs when all the driver outputs are in the high
impedance state. The lines float, perhaps being pulled to the high or
low state by noise or other voltages on the line.
Without fail safe open circuit detection false start bits are
detected by the receivers, either corrupting good communications
or causing noise to masquerade as good data.
The on board fail safe open circuit detection causes the
receiver to go to a known, pre-determined state and prevents false
start bits and bad data being detected during open circuits.
Fail Safe Short Circuit Protection.
Short circuits are when the two lines of a twisted pair are

Hardware Configuration AT & OPTO DUAL RS422/485
Chapter 2 Page 10
connected together. This occurs due to either accidental damage to
the cable or due to failure of one or more transmitter/receivers on
the line. The short circuit condition is dangerous since damage to
the receiver may occur and communication may be corrupted or
prevented.
The on board fail safe short circuit detection prevents the line
impedance from going to zero and thus protects the inputs of
receivers and the outputs of drivers.
Figure 2-1a). AT Dual Port RS422/485 Card Layout.
COM 1 COM 2 COM 3 COM 4 COM 5 COM 6 COM 7 COM 8
SERIAL 2
SERIAL 1
RXD 2+
RXD 2-
RXD 1+
RXD 1-
TXD 2+
TXD 2-
TXD 1+
TXD 1-
RS485 MULTIPLEX
FORCE CTS 1
RXD 1
TXD 1
TRUE
DIS
GATE
FORCE CTS 2
RXD 2
TXD 2
TRUE
DIS
GATE
RS485 GATING
IRQ 7 IRQ 6 IRQ 5 IRQ 4 IRQ 3 IRQ 2 IRQ 10 IRQ 11 IRQ 12 IRQ 15
SERIAL 1
SERIAL 2

AT & OPTO DUAL RS422/485 Hardware Configuration
Chapter 2 Page 11
Figure 2.1b) - Opto Isolated AT Dual Port RS422/485
Card Layout
COM 1 COM 2 COM 3 COM 4 COM 5 COM 6 COM 7 COM 8
SERIAL 2
SERIAL 1
RXD 2+
RXD 2-
RXD 1+
RXD 1-
TXD 2+
TXD 2-
TXD 1+
TXD 1-
RS485 MULTIPLEX
FORCE CTS 1
RXD 1
TXD 1
TRUE
DIS
GATE
FORCE CTS 2
RXD 2
TXD 2
TRUE
DIS
GATE
RS485 GATING
IRQ 7 IRQ 6 IRQ 5 IRQ 4 IRQ 3 IRQ 2 IRQ 10 IRQ 11 IRQ 12 IRQ 15
SERIAL 1
SERIAL 2
Fucknut
PIN#1
LPT3 LPT2 LPT1
PRINTER
PRINTER
Configuring The RS422 Card.
In the state it leaves our factory, the Serial Solutions
RS422/485 card is ready to plug straight into an IBM compatible
PC computer. It has been configured for RS422 operation.
So, unless you have GOOD REASON, you do not need to alter
its default setting.
However, due to the presence of other serial port cards in the
PC, your SERIAL SOLUTION card may need configuring to suit
your setup. The layout of the cards is given in Figures 2-1a) and 2-
1b), above..

Hardware Configuration AT & OPTO DUAL RS422/485
Chapter 2 Page 12
Serial Port Jumpers.
Serial port 1 drives the UPPER 9 pin D connector and serial
port 2 drives the LOWER 9 pin D connector. There are 4 sets of
jumpers associated with the two ports; their locations on each card
are show in the Table below:
Table 2-1. Serial Port Jumper Locations
AT Dual RS422/485 Opto Iso RS422/485
COM Port Select Bottom centre Middle left of centre
IRQ Select Bottom left Bottom Left
RS485 Gating Top left of centre Top left of centre
RS485 Multiplexing Middle right of centre Top right of centre
Figure 2-2. Port Address Jumper Block.
JUMPER PORT ADDRESS NORMAL IRQ ALLOCATION.
COM8 01B8hex IRQ 3.
COM7 01B0hex IRQ 3.
COM6 01A8hex IRQ 3.
COM5 01A0hex IRQ 3.
COM4 02E8hex IRQ 3.
COM3 03E8hex IRQ 3. DEFAULT SERIAL 2
COM2 02F8hex IRQ 3. DEFAULT SERIAL 1
COM1 03F8hex IRQ 4.
1 2 3 4 5 6 7 8

AT & OPTO DUAL RS422/485 Hardware Configuration
Chapter 2 Page 13
Serial Port Address Selection.
The movable jumper on the address jumper block, (shown
below with default settings), is used to specify the I/O address of
the first serial port. This determines whether the card is configured
as COM1, COM2, COM3, COM4 or COM5- COM8.
COM 1 COM 2 COM 3 COM 4 COM 5 COM 6
COM 7 COM 8
SERIAL 2
SERIAL 1
The default, factory set position for serial #1 is COM2 and
for serial #2 is COM3. Depending on how many other serial port
cards are already installed in the PC the I/O address may need to be
changed.
The COM5 to COM8 addresses, 01A0 hex to 01B8 hex
will not work on the genuine original 8088 IBM PC but are valid
for most 8088 PC's and all machines of Pentium Pro standard and
below. Below is shown a representation of the IRQ Port jumper
block on the AT Dual RS422/48, with factory defaults.
Serial Port IRQ Interrupt Jumper Selection.
By referring to Figures 2-1a) and/or 2.1b) locate, the Serial
Port IRQ interrupt jumper block (pictured below with default
settings) at the lower left of the board. The movable jumper on the
jumper block is used to specify which hardware interrupt is to be
generated by the PC serial port.
SERIAL 1
SERIAL 2

Hardware Configuration AT & OPTO DUAL RS422/485
Chapter 2 Page 14
Two rows of jumpers are visible, the top row corresponding
to serial #1 and the bottom row to serial #2, by placing a jumper
over two pins in the same row an interrupt vector may be assigned
to a serial port. NOTE: It is vitally important not to place a jumper
over pins between the two rows, damage to your card and/or PC
may result from this.
Most users will require that the IRQ is set to correspond to
serial port address selection. However, a serial port that is USING
interrupts must not share the same IRQ line as another serial port
that is USING interrupts AT THE SAME TIME, otherwise some
interrupts will be missed. IE no two ports may use the same IRQ
line simultaneously.