Brainboxes CC-346, PCI Quad 422, PCI Quad 485 User Manual

PCI Quad 422/485 Card

By Paul D. Sinclair.

PCI Quad 422/485 Card Contents • i

Contents

Introduction 1

Guarantee. ......................................................................................................................1

Copyright.......................................................................................................................1

BRAIN BOXES Limited.................................................................................................1

ACKNOWLEDGEMENTS. ...........................................................................................1

Chapter 1 Serial Solutions 2

Serial Solutions For DOS................................................................................................2

Serial Solutions For Windows 3.x...................................................................................3

Serial Solutions For Windows 9x....................................................................................4

Serial Solutions For Windows NT...................................................................................4

Serial Solutions for Windows 2000.................................................................................4

Complete Documentation and Technical Backup.............................................................5

Chapter 2 Hardware Configration 6

Introduction....................................................................................................................6

Card Features..................................................................................................................6

Autogating......................................................................................................................7

Card Layout and Specifications....................................................................................... 7

Port Pinouts. .................................................................................................................. .8

Configuring the Card......................................................................................................8

RS485 Multiplex Jumper Settings...................................................................................9

Chapter 3 Installing the Card 10

STEP 1:Remove Cover Mounting Screws.....................................................................10

STEP 2:Remove The PC Cover.....................................................................................10

STEP 3: Remove the Blanking Cover............................................................................11

STEP 4: I ns ert The Ca r d ..............................................................................................11

STEP 5: Secure the Card into Your PC..........................................................................11

STEP 6: Replace Cover.................................................................................................12

STEP 7: Reattach All Cables.........................................................................................12

Problems!.....................................................................................................................12

Chapter 4 DOS Software Configration 13

Introduction..................................................................................................................13

Determining PCI RS422/485 Resources........................................................................13

NEWCOM.SYS Parameters..........................................................................................13

Configuring And Installing NEWCOM.SYS.................................................................14

Modifying Command Line Parameters. .........................................................................15

Chapter 5 Windows 3.x Software Configuration. 16

Introduction..................................................................................................................16

Determining PCI Resources.........................................................................................16

Windows 3.x Driver Installation....................................................................................16

Serial Port Installation...................................................................................................17

PCI Quad 422/485 Card Contents • ii

Configuring The COM Ports.........................................................................................19

Deleting Ports in Windows............................................................................................20

Chapter 6 Windows 95 Software Configuration 21

Introduction..................................................................................................................21

Card Settings................................................................................................................24

Port Settings................................................................................................................. 26

Serial Solutions Port Settings ........................................................................................28

Chapter 7 Windows 98/Millenium Installation. 30

Checking the Installation...............................................................................................32

Card Settings................................................................................................................33

Port Settings................................................................................................................. 35

Chapter 8 Windows NT 4.0 Installation. 39

Introduction..................................................................................................................39

Software Installation.....................................................................................................39

Examining Card Configuration......................................................................................40

Card Setup....................................................................................................................40

Configuring Ports.........................................................................................................41

Advanced Port Settings.................................................................................................42

Uninstalling Serial Solutions PCI. .................................................................................43

Chapter 9 Windows 2000 Installation 44

Software Installation.....................................................................................................44

Checking your Installation............................................................................................47

Chapter 10 Optional RS422/485 Operation 48

The RS422 Standard.....................................................................................................48

The RS485 Standard.....................................................................................................48

Terminating Impedance’s..............................................................................................48

Fail Safe Open Circuit Detection...................................................................................49

Fail Safe Short Circuit Protection.................................................................................. 49

RS422 Operation. ......................................................................................................... 49

RS422 Serial Port Cables..............................................................................................49

Serial Port 1 To Other PC Cable....................................................................................50

RS485 Operation. ......................................................................................................... 50

RS485 Cable.................................................................................................................50

RS485 One Talker - Many Listeners, Half Duplex.........................................................51

Half Duplex Settings of RS485 Multiplex.....................................................................51

RS485 Many Talkers- Many Listeners, Half Duplex......................................................51

RS485 Many Talkers- Many Listeners, Full Duplex......................................................52

Optional Grounding Arrangements................................................................................ 53

Index 54

PCI Quad 422/485 Card Introduction • 1

Introduction

Guarantee.

BRAIN BOXES LIMITED guarantee your Serial Port Card for a full 36 months
from pu rcha s e, par ts an d labour, provid ed it has been used in the specifi ed
manner. In the unlikely event of failure return your interface to BRAIN BOXES
LIMITED or to your Dealer, with proof of purchase, who will determine
whether to repair or replace this product with an equivalent unit.

Copyright.

COPYRIGHT © 1985-2000 BRAIN BOXES LIMITED.
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 LIMITED.

BRAIN BOXES Limited.

Unit 3C, Wavertree Boulevard South,
Wavert ree Tech nology Par k ,
Liverpool, L7 9P F,
England.

Telephone: [phone]
Fax: [phone]
E-mail: [e-mail]

/sa les@brainbox es.com

Web: www.brainboxes.com

ACKNOWLEDGEMENTS.

BRAIN BO X ES is a trademark of BRAIN BO XES LI M ITED.
IBM, COMPAQ, Hewlett Packard, H.P. and EPSON are trademarks of the

releva nt companies . OS/2 a nd Microchannel Arch itecture ar e trad emarks of
IBM. W ind ows is a trademark of M icros oft.

PCI Quad 422/485 Card Chapter 1 Serial Solutions • 2

Chapter 1 Serial Solutions

This chapter is a brief description of the Serial Solutions software package; this
can also be purchased SEPARATELY and is available from YOUR DEALER.

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 9x
Serial Solutions for Windows NT
Serial Solutions for Windows 2000
All the Serial Solutions drivers have the following features: -
Drivers for PC FIFO UARTs e.g. 16550 as well as the new improved 32 byte

16650 and 64 byte 16750 UARTs.
Support for any mix of RS232, RS422, and RS485 handshake schemes.
Support for wider range of Baud rates and for more than 4 serial ports.

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 handl er 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 bo th hardware handshaking
using any combination of the DTR, DSR, CTS, RTS, and DCD lines, and a
software han d shake usin g t he 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, includ ing the p ort address, I RQ line used, the baud rate , p arity
and data and stop bit options. 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

PCI Quad 422/485 Card Chapter 1 Serial Solutions • 3

The EASY disk contains short, simple to understand and use EASYBAS,
EASYC and ASYPAS programs, providing straight forward, file type I/O to
serial ports with debug information. Use these FIRST, base your 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 p orts. They contain m any lines of code an d are thus h arder to gr asp. They
demonstrate in depth serial port programming in a variety of languages but th ey
are also useful tools for using serial devices.

Comtest.exe

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 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, p arity enable and
start stop bi t is performed. There is no need for a second serial port or a cable
when using this utility.

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 th e 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

Replacem ent for C O MM .DRV.

LynxAPI.dll

Enhan cement to the Wi ndows Comms AP I ’s allowing support for more than 9
ports.

Term.exe

Terminal program.

EasyCWIN

C source cod e, project fi les and read y to run. ex e progr am for a n easy to
understand Windows terminal program. Learn how to write Windows comms
apps correctly the easy way.

PCI Quad 422/485 Card Chapter 1 Serial Solutions • 4

Serial Solutions For Windows 9x.

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 con sists of the
following programs: -

PCI.inf

The information files to aid the

ISA.inf

Installation process "Have Disk....”

ssmodem.inf

Setup file for Serial Solutions modems.

sscardui.dll ssportui.dll

The device manager configuration DLLs and…

ssenum.vxd ssv485.vxd

…the vi rtua l device drivers p roviding the shared

ssvel.vxd ssmult.vxd ssm485.vxd

interrupt handlers and dispatch routines etc for the various Serial Solutions
serial cards.

Serial Solutions For Windows NT.

Windows NT has an improved communication API and directly supports up to
255 ports. No extra driver is nece s s ary for Window s NT to drive multiport c ards.
Serial Solutions for Windows NT consists of the following programs: -

Setup.exe

Expands into the Control Panel applet and associated files which allows the
configuration of all ports on Serial Solutions serial cards.

Ssmodem.inf

Setup file for Serial Solutions modems.

Serial Solutions for Windows 2000

BBISA.inf, BBMulti.inf, BBPCMCIA.inf

The ISA...PC I...and PCM CIA c ard info rmation f iles , w hich make the installation
with the hardware installation wizard possible.

BBPort.inf

Information file, which contains information for the installation of individual
ports.

ssInstal.sys

The driver, which handles the installation and setup of each card, be it PCI, ISA
or PCMCIA.

PCI Quad 422/485 Card Chapter 1 Serial Solutions • 5

SsPort.sys

The driver, which gets COM ports going.

SsPar.sys

The driver for Parallel ports

SsCard.dll

A Dynamic Link Library, wh ich provides a user interface to configure cards and
their ports under Device Manager / Multi-port serial adapters

SsCard.hlp

The help file for the SsCard.dll user interface.

Complete Documentation and Technical Backup.

We believe in supplying complete documen ta t ion with every package we sell.
We guarantee your Serial Solution Software package for a full 12 months from
purchase. A complete technical backup service is a vaila ble to ensure that you get
the maximum performance out of your investment.

PCI Quad 422/485 Card Chapter 2 Hardware Configration • 6

Chapter 2 Hardware
Configration

Introduction

This chapter detai ls the specifications of the PCI quad RS422/485 card and
explains how to configure the RS485 Multiplex jumpers present on both cards.
These half-sized cards will work happily in any PCI 2.0 or greater compliant PC
compatible.

Card Features.

½

Four independent 9 pin D RS422/485 Serial ports.

½

Reliable communications up to 4000 feet, 1.2 Kilometres.

½

16950 FIFO provides 128-byte input an d 128-byte output buffer on each
port.

½

Maximum baud rate of 912600 Baud (1 Megabaud).

½

Word length of 5, 6, 7 or 8 bits.

½

Even, Odd, None, Mark or Space parity options.

½

1 start bit always sent.

½

1, (1.5 for 5-bit data word length), or 2 stop bits.

½

TXD, RXD, RTS, a nd CTS signals.

½

RS485 TXD/RXD multiplex selectable by jumpers: - either FULL
DUPLEX or HALF -DUPLEX.

½

Fully double buffered for reliable asynchronous operation.

½

High-speed integrated circuitry ensures operation with fast PC’s e.g. 800
MHz Pentium II WITHOUT extra wait states.

½

Autogating low level RS485 half duplex (2 wire) control

Clock Input: 60.00mHz
Drivers: SN75174
High Level Voltage: 3.7V typical at 33mA source
Low Level Vol t age: 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.

PCI Quad 422/485 Card Chapter 2 Hardware Configration • 7

Autogating.

Multitasking operating systems, like Windows 95, Windows NT, OS/2 and
UNIX, cannot successfully use the RTS line to control the gating of th e PC’s
transmitter. Whilst they can set the RTS line true just before the data
transmission starts, they cannot set the RTS line false quickly enough after the
data has gone. This is due to the time slicing mechanism used by these
multitasking operating systems. The interrupt service routines in multitasking
OS’s have a long latency, i.e. time taken to switch context from the foreground
program to the interrupt routine. During this time, the first few bytes of the
external devices reply to the PC may be lost since the serial port transmitter is
still gated onto the twisted pair cable.

To overcome this problem, The 16950 has on chip autogating. This option
requires a special device dr iver (supplied) this automatically detects the start of
the PC’s data tr a nsmission s, and gat es t he PC’s transmitter onto the twisted pair
cable. It then automatically detects the last stop bit being sent and gates the port
off th e twisted pair cable but to an application on the host PC. It looks just like
an ordina ry RS232 COM port. Autogating for half duplex operation is a
necessity for Windows 95, NT and Windows 2000.

Card Layout and Specifications.

AT Quad 4 Port RS422/485 Specifications:

Dimensions: 4.2 x 6.3 in , 106 x 160 mm
I/O Connection: 37 way female D connector to 4 serial ports
Serial Port 1: 9 pin Mal e D type.
Serial Port 2: 9 pin Mal e D type.
Serial Port 3: 9 pin Mal e D type.
Serial Port 4: 9 pin Mal e D type.

PCI Quad 422/485 Card Chapter 2 Hardware Configration • 8

Port Pinouts.

9 Pin D Connector

PIN 5 - GROUND (GND)

PIN 1 - TRANSMITTED DATA (TXD-)

PIN 6 - RECEIVED DATA (RXD-)

PIN 8 - CLEAR TO SEND (CTS-)

PIN 3 - REQUEST TO SEND (RTS-)

PIN 2 - TRANSMITTED DATA (TXD+)

PIN 4 - REQUEST TO SEND (RTS+)

PIN 7 - RECEIVED DATA (RXD+)

PIN 9 - CLEAR TO SEND (CTS+)

37 Way D Connector

3,1*1'

3,1576

3,1576

3,17;'

3,17;'

3,1&76

3,1&76

3,15;'

3,15;'

3,1*1'

3,1576

3,1576

3,17;'

3,17;'

3,1&76

3,1&76

3,15;'

3,15;'

3,1*5281'
3,1&76
3,1&76
3,15;'
3,15;'
3,1*1'

3,1576
3,17;'
3,17;'
3,1&76
3,1&76
3,15;'
3,15;'
3,1*1'
3,1576
3,1576
3,17;'
3,17;'

3,1576

Configuring the Card.

PCI cards require no hardware configuration for IRQ and address allocation ­this is done automatically at start up by the PC. However, the PCI quad
RS422/485 has four sets of jumpers for configuration of RS485 multiplex modes
for each port, how to configure these jumpers is shown bel ow.

PCI Quad 422/485 Card Chapter 2 Hardware Configration • 9

RS485 Multiplex Jumper Settings.

The RS485 Multiplex jumper block, is shown below with default settings of no
jumpers present (both ports full duplex).

Where:
TX/RX1+ and TX/RX1- control port 1 RS485 multiplexing.
TX/RX2+ and TX/RX2- control port 2 RS485 multiplexing.
TX/RX3+ and TX/RX3- control port 3 RS485 multiplexing.
TX/RX4+ and TX/RX4- control port 4 RS485 multiplexing.

Full Duplex Settings(port 1).

Both jumpers l eft unconnected ( not sh orted).

Half Duplex Settings(port 1).

Both jumpers shorted, causing the RXD- & TXD- and the RXD+ & TXD+
signals to short together at the 9-pin connector. The multiplex jumpers should
only be set for RS485 Half Duplex operation, when one twisted pair is used to
interconnect both tran smit and r eceive lin es.

These settings are the same for each port.

NOTE: Any changes to RS485 Multiplex Operation must be accompanied with

appropri ate changes t o the driver softwa re
For further details on th e RS422 and RS485 standar d, pi nouts, half duplex and

full duplex RS485 systems, wiring diagrams an d optional grounding diagra m s
refer to Chapter 10 - "Optional RS422/485 Operation."

PCI Quad 422/485 Card Chapter 3 Installing the Card • 10

Chapter 3 Installing the Card

NOTE: Always turn the computer OFF
before installing or removing any interface
board!

STEP 1:Remove Cover Mounting Screws.

Then using a screwdriver, remove the cover mounting screws on the back panel
of the PC system unit.

STEP 2:Remove The PC Cover.

Next , re move the PC’s cover by sliding it forward and up. It usually helps to
disconnect the keyboard from the PC since it tends to get in the way when the
case is removed.

PCI Quad 422/485 Card Chapter 3 Installing the Card • 11

STEP 3: Remove the Blanking Cover.

Choose an empty expansion slot. This Card will fit into one of th e white PCI
slot s on your mother boad. Remove the bla nking c ove r protectin g th e s lot on th e
PC back panel. KEEP the blanking cover screw safely for later.

STEP 4: Insert The Card.

Now insert the card in the slot. Be careful to ensure that the gold plated pcb
fingers fits neatly in to the I/O expansion connector . Press down firmly but
evenly on t he top of the card .

STEP 5: Secure the Card into Your PC

The 9 pin D connector should fit neatly through the slot’s aperture to the outside
world.

Use the screw kept back from the blanking cover to screw the retaining bracket
into the PC back panel housing.

PCI Quad 422/485 Card Chapter 3 Installing the Card • 12

STEP 6: Replace Cover

Now replace the system uni t’s cover by carefully sliding it down and over th e
system unit. Rep lace the cover screws.

STEP 7: Reattach All Cables

After attaching all the monitor and keyboard cables, power up the PC. Do not
forget the mains p ower cable!

The PC should power on in the normal way.

Problems!

If the system fails to power up normally check the following:
Ensure that the PC Serial card is installed correctly.
nsure th at oth er car d s in the PC h ave not been u p s et.
Ensure that the power is connected and the P C is switc he d O N !
If all these have been checked and the PC still does not power up then inspect

the area surrounding the card to ensure that any potentially harmful bits of metal
etc. a re not presen t, if the pr oblem persists ask your deal er to check the card or
contact [e-mail]

PCI Quad 422/485 Card Chapter 4 DOS Software Configration • 13

Chapter 4 DOS Software
Configration

Introduction.

This section contains the installation procedures of the PCI VELOCITY
RS422/485 card, with the DOS, Windows 3.x Windows 95, Windows
98/Millennium, Windows NT and Windows 2000 operating systems.

The setup procedures in this chapter assume that your PC has only on e serial
port present.

Determining PCI RS422/485 Resources.

Insert card into PC, as described in .
Run BBCARDS.EXE, from the supplied Serial Solutions CDROM by typing the

following:
D:\diskimg\ssutil\pci\BBCARDS
Wher e D :\ is the Letter of your CDROM drive
BBCARDS.EXE will return a string that looks similar to the following (values

contained in the string may differ in individual PC’s due to res o urce av ailab ility ):

card 1 is on bus 0, device 16, function 0
Card ID=5, revision 1: 4 Port Velocity RS422/485

interrupt line 11 has been assigned
4 sets of 16550-compatible registers are at I/O
address 0140

Baud clock control is at I/O address 02d0
Write 0xf6 for /8 (default), 0xf2 for /4, 0xd6 for /2,
0xd2 for /1.

Note down IRQ and I/O which in this case:
The IRQ = 11
The I/O address = 0140

NEWCOM.SYS Parameters.

The NewCOM.SYS device driver in cluded with the PCI RS422/485 driver software is used to set up the

card in DOS and has the following syn tax:

NEWCOM.SYS /A port address, /I IRQ,range /B number buffer /S buffer /H hardware handshake

Where:

/A port address specifies COM p ort n u mber followed by a h ex adecimal add ress

in the form /Ax,y where x is COM port range and y is I/O address.

PCI Quad 422/485 Card Chapter 4 DOS Software Configration • 14

/I IRQ, range specifies card interrupt and COM port range. The COM port range
specifies the COM p ort(s). Rang e may be a sin g le port OR a range of port s .

/B number buffer is used to set the number of pairs of buffers to be allocated to
ports and is a decimal number in the range 1-maxport.

/S buffer Set size of all buffers in bytes, buffer is rounded to the nearest power
of 2 and must be a decimal number in the range 32 to 32768. For any serial port
open e d two buffers of si ze buffer are al locat e d, on e for input an d the other for
output.

/H hardware handsha k e selects which hardware handshake type to use on th e
specified ports. This is used in the following manner: /H range, hs where range
specifies the COM p ort or p orts and hs selects h a ndshak e type. Han d shake types
available are:

Type 1 RS422 RTS/CTS - The PC only transmits when CTS is input

tru e. When the PC is able to receive its s ets RTS output true. The DSR and DCD
inputs are ignored. The DTR outpu t line is s et true just in case the external serial
device needs a true signal.

Type 2 RS485 Half duplex - Before any data is sent the PC sets RTS

true, after the last byte in the buffer has been sent the PC sets RTS false. RTS is
used as a transmit gating control. The CTS, DSR and DCD inputs are ignored.
The DTR output line is s et true just in case the external serial de vice needs a true
signal.

Type 3 RS485 Send only - This is a half duplex, transmit only

handshake. The PC transmits w he ne ver it wishes, it cannot receive any data. The
CTS, DSR and DCD inputs are ignored. The RTS output line is set true just in
case the external s erial device need s a tru e s igna l.

Type 4 3 Wir e Ha ndsh ake - Really no handsh ake at all si nce th e P C

transmits irrespective of the handshake lines. The 3 wires are TxD, RxD and
Ground, no other lines are required. Thus th e CTS, DSR and DCD in puts are
ignored. The RTS and DTR output lines are set true just in case the external
serial device needs a t rue sig nal.

Note: If hardware handshaking is not specified in the NEWCOM.SYS
parameters, type 4, 3 Wire Handshake is selected automatically.

Configuring And Installing NEWCOM.SYS

To load the Serial Solutions for DOS device driver an entry needs to be added to
the CONFIG.SYS file. Any simple text editor, EDIT for example, can edit the
CONFIG.SYS file for example. The installation procedure given below is for a
PCI RS422/485 as COM 5-8.

The p arameter required by the NEWCOM.SYS d river are those ret u rned by the
BBCARDS.EXE application earlier. A brief explanation for the parameters
required by NEWCOM.SYS follows:

Port Address.

/A5-8,0140
COM ports 5,6,7 and 8 ar e defined, with an i/ o addr ess range that begins at

0140h and al l subsequent ports have an i/o addr ess tha t is 8 h i gher than the

PCI Quad 422/485 Card Chapter 4 DOS Software Configration • 15

previous. i.e. if COM5 has an address of 0140h, then COM6 will have an
address of 0148h, COM7 an address of 0150h etc.

IRQ, Rang e .

/I 11,5
11 is the IRQ and since the COM por t is COM5 is entered 5.

Number Buffer.

/B8 buffers are defined, though only four ports are in use –this is because bu ffers
in DOS are assigned in a sequential order from COM1. Since the PCI Quad
RS232 has been assigned COM port values of 5 to 8, all precedin g COM port s ,
must have buffers assigned to th em also.

Buffer Size.

/S512
Buffer size set to 512 bytes.

Hardware Handshaking.

/H,4
Type 4, 3 Wire Handshake selected for all ports. Type 4, 3 Wire Handshake

selected for all p orts.

Modifying Command Line Parameters.

When "assembled" the NEWCOM.SYS command line looks like…

DEVICE=NEWCOM.SYS /A5-8,0140 /I 11,5-8 /B8 /S 512 /H,4
…and should be entered into the C O NFIG.S Y S file. Once you are sure that these

parameters have been entered correctly, restart your PC and your PCI Quad
RS422/485 Cardshould be ready to use immediately.

PCI Quad 422/485 Card Chapter 5 Windows 3.x Software Configuration. • 16

Chapter 5 Windows 3.x
Software Configuration.

Introduction

The Windows 3.x installation procedure consists of two steps after the PCI
RS422/485 card is inserted:

1. Determinin g t he resources that the PCI RS422/485 card has claimed.

2.Informing Windows 3.x of those resources.
Whenever certain values have been entered or changed in the hardware settings

window, a message p ro mp ting to restart Windo ws will appear. Only after having
made ALL the necessary chan ges restart Windows so that the new settings come
into effect.

Determining PCI Resources.

Insert the card into a PC, as described in Chapter 3 .

Run BBCARDS.EXE, from the suppli ed “Serial Solutions CDROM” by typing
the following:

D:\diskimg\ssutil\pci\BBCARDS

Wher e D :\ is the Letter of your CDROM drive
BBCARDS.EXE will return a string that looks similar to the following (values

contained in the string may differ in individual PC's d ue to resou rce availability ):

card 1 is on bus 0, device 16, function 0
Card ID=5, revision 1: 4 Port Velocity RS422/485

interrupt line 11 has been assigned
4 sets of 16550-compatible registers

are at I/O address 0140
Baud clock control is at I/O address 02d0
Write 0xf6 for /8 (default), 0xf2 for /4, 0xd6 for /2,
0xd2 for /1.

Note down IRQ and I/O which in this case:
The IRQ = 11
The I/O address = 0140

Windows 3.x Driver Installation.

Place the supplied Serial Solutions CDROM in a suitable drive. From File
Man ager choose ‘Run’ an d enter D:\diskimg\sswin3x\setup (where D:
is the path to the CDROM drive Con tain ing the disk).

PCI Quad 422/485 Card Chapter 5 Windows 3.x Software Configuration. • 17

Click OK, the Setup Program Main Screen is displayed:

By default, all component options will be installed, selecting the "Del All"
butto n will se lect all installed components for deletion and "Add A ll" chooses all
uninstalled components for installation; options may n ot be changed when the
compon ents are installed. For further details on the Component Options consult
the README.TXT file on the supplied disk.

If only logical ports COM1 to COM9 are to be used th en de-select the Comms
API library op tion in the "Install" column. This library is only ne cessary to allow
the use of logical ports greater th a n COM9 e.g. COM10, COM11 etc.

When you h ave made your choice of Component Option s click Continue and
when the setu p program has finish ed s elect th e Done button.

Note: If the Serial Port driver options has been selected, after the setup program
has finished, Windows will display a restart message - answer Yes and Serial
Solutions will be ready to run upon Windows restarting.

Serial Port Installation.

From Main, s elect Control Panel:
Double -click on Serial Ports:

PCI Quad 422/485 Card Chapter 5 Windows 3.x Software Configuration. • 18

The following dialogue will be displayed:

To add a COM port:
Click on the add button and a Window similar to the following will be

displayed:

In Standard Settings:
In the COM Base field, enter the value 0140.
Note: COM ports are defined with an i/o address range, which in th is case,

begins at 0140 and all subsequent ports have an i/o address tha t is 8 higher tha n
the p revious. i.e. i f COM2 has an a ddress of 0140h, then COM3 h a s an address
of 0148h.

In t he IRQ field, enter the value 1 1.
Note: T he values u s e d in the above sect ion were those return ed by the

BBCARDS program, as described in the above sect ion.
When you h ave fini shed, click on OK. A restart message will be displayed; to

save time only restart when both ports have been added and correctly configured.

After adding the COM port the COM Por ts Window will look similar to the
following:

PCI Quad 422/485 Card Chapter 5 Windows 3.x Software Configuration. • 19

Configuring The COM Ports.

From the COM P orts win dow choose the p ort that you wish to configu re an d
click on Settings -

the following dialogue will be displayed:

Note: A port that has been added has the default values of:

Baud Rate: 9600
Data Bits: 8
Parity: None
top Bits: 1.0
Flow: None

Change the communications Settings in the COM Ports to match the baud rate,
parity settings etc. of the remote serial device.

PCI Quad 422/485 Card Chapter 5 Windows 3.x Software Configuration. • 20

Deleting Ports in Windows.

The Delete button can be used to discard the entries of ports that have been
removed fr om the system.

Note. Never try to leave out a serial port number when using the delete button,
because Windows may automatically shift serial port numbers which results in a
mis-match of settings in the Serial Ports Applet (COM1-COM4 only).

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 21

Chapter 6 Windows 95
Software Configuration

Introduction

To obtain a troubl e free mix-and -match of the C OM ports:
Switch off your computer, insert your PCI RS422/485 card into a free PCI slot,

as described in Chapter 3, an d switch your computer on again.
During the booting process, Windows 95 will detect the PCI Velocity

RS422/485, but will display it simply as a "PCI CARD", and you will briefly see
a message box to this effect.

Windows will then display the "Update Device Driver Wizard", which asks you
to “insert any disk which came with the PCI card”. Insert the Serial Solutions
CD ROM into an appropriate drive and click 'Next'.

The Wizard should then display the following:

Click Other Locations

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 22

In the location space type <drive>:\diskimg\sswin9x where drive is th e
appropriate letter for your CDROM drive

Click OK

Th e s c reen shot above shows that th e Update Device Driver Wizard has
found a suitable driver and the location of that driver.

Click Finish

Click OK

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 23

In the copy files from space type <drive>:\diskimg\sswin9x where drive is
the appropriate letter for your CDROM drive

After copying th e file, Windows 95 will then detect each of the serial ports in
turn and install them as communications ports.

Using the right-hand mouse button click on the My Computer icon on your
desktop.

Click on Properties.

Select on the Device Manager tab

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 24

When the Device Manager is viewed the PCI Quad Velocity R422/485 card
will appear under the Multi-function adapters branch. Also, four Velocity
RS485 Ports will appear under the Ports (COM & LPT) branch.

For most users who have 4 or less COM por ts the new ports will appear as
COM5 -8 as pictured above, for users with more tha n 5 C O M ports the n ew port
will appear as the first available COM ports.

Card Settings

Using the right-hand mouse button click on the My Computer icon on your
desktop.

Click on Properties.

Click on the Device Manager tab

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 25

Select t he PCI Quad Velocity RS422/485 card from the Multi-Function
Adapter entry in Device Manager serial and click on properties to view the

cards general properties.

Click on the Serial Solutions tab Solution s tab produces.

In this window, the COM port assignment may be changed, simply by selecting
a new COM port value from the pull down menu relevant to the port. However,
COM port usage other than those for the PCI Quad Velocity RS422/485 card
itsel f a re not checked, so i t is ad vi s able to fir s t check wh ich COM ports a re in
use - por t availability can be checked by viewing the Device Manager:

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 26

All COM ports present will be listed under the entry "Ports (COM & LPT)."
Th e above screens hots ind icat e s that CO M 2 - 4 and COM9 and above are not
installed, and therefore may be used.

The Maximum Baud Rate Setting for all ports on the card may also be set
from this window. This settting will make the maximum baud rates of all the
ports on this card equal to whatever is set. Individual ports may h ave their
settings changed as shown in Port Settings

Port Settings

Using the right-hand mouse button click on the My Computer icon on your
desktop.

Click on Properties.

Click on the Device Manager tab

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 27

Double clicking on a Velocity RS485 Port entry from the entry "Ports (Com &
LPT)" branch in Device Manager will the display general properties window

for the selected p ort (i n th is case COM5).

Selecting the Port Settings tab produces:

Settings available in this win dow are:
Baud Rate* - deter mines the baud rate at whi ch th e selected port operates, the

maximum value available is dependant upon the Maximum Baud Rate Setting
(see below.)

Data Bits.*
Parity.*
Stop Bits.*
Flow Contr ol *
*These set t i ng s are dependent upon the devic e being used.

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 28

Maximum Baud Rate Setting - four val ues are available, which selects th e
maximum baud rate at which the port may operate. The table below, indicates
the ranges of baud rate values available at the Maximum Baud Rate Settings.

Maximum Baud Rate

115200 230400 460800 921600

50 100 200 400

75 150 300 600
110 220 440 880
150 300 600 1200
300 600 1200 2400
600 1200 2400 4800

1200 2400 4800 9600
1800 3600 7200 1440
2000 4000 8000 16000
2400 4800 9600 19200
3600 7200 14400 28800
4800 9600 19200 38400
7200 14400 28800 57600

9600 19200 38400 76800
19200 38400 76800 153600
38400 76800 153600 230400
57600 115200 230400 460800

115200 230400 460800 921600

Note: Many serial comms applications will not actually register the ports as
ru nning at ba ud r ates of above 115200.

Restore Defa ults - when clicked, resets the selected COM port to the following
values:

Baud Rate: 9600
Data Bits: 8
Parity: None
Stop Bits: 1
Flow Control: Xon / Xoff
Maximum Baud Rate Setting: 115,200

Serial Solutions Port Settings

Clicking on the Serial Solutions tab will display:

PCI Quad 422/485 Card Chapter 6 Windows 95 Software Configuration • 29

Settings available in this win dow are:

FIFO Sett i ngs.

Enable FIFO - turns the selected ports FIFO buffer on or off. It is strongly

recommended that the FIFO for both por ts is left enabled.
Extend FI FO - when checked, extend s the sel ected port s F I F O bu ffer from 16

to 64 bytes.
Receive Buffer - These settings allow the selection of a receiver FIFO tr igger

setting. Selecting a low value will allow the interrupt to be serviced quicker,
which is good for slow machines. If you have a fast machine, setting a high
value will give you more time for multi-tasking operations.

Transmit Buffer - These s e ttings allo w the se le ctio n o f a transmitter F I F O t rig g er
setting. Selecting a low value w ill send fewer data-byte s p er interrupt, and this is
recommended if you ar e communicating to a slower machine. Selecting a high
value will send more data-bytes per interrupt, and will give more time for multi­tasking operations.

485 Mode offers the options:

Half Duplex / Full Duplex(default) - are used in conjunction with the RS485

Multiplex Jumper Settings.
NOTE: These software settings must match the RS485 Multiplex Jumper

configuration, as described in the section "RS485 Multiplex Jumper Settings"
in Chapter 2, to ensure accurate and error free data transmission.

CTS Hold True, determines wh ether the CTS handshake signal is INPUT from
the ex tern al ser ial devi ce or is permanently forced tru e on th e card. The serial
ports own RTS OUTPUT handshak e sig nals are always taken out to the serial
port connect or.

Restore - when this button is clicked the settings in the current window will be
reset to the default values of:

Enable FIFO: On (C hecked)
Extend FIFO: Off (Unchecked)
Receive Buffer: 3

rd

from left.
Transmit Buffer: 16
485 Mode: Full dupl ex.

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 30

Chapter 7 Windows
98/Millenium Installation.

To obtain a troubl e free mix-and -match of the C OM ports:
Switch off your computer, insert your PCI RS422/485 card into a free PCI slot,

as described in , and switch your computer on again .
During the booting process, Windows 98 will detect the PCI Velocity

RS422/485, but will display it simply as a "PCI CARD", and you will briefly see
a message box to this effect.

Insert the Serial Solutions CD ROM into an appropriate drive and click ’Next’.

Select Search for the best driver for your device.
Click Next

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 31

Click Specify a location
In the location space type <drive>:\diskimg\sswin9x where drive is th e

appropriate letter for your CDROM drive
Click Next

Click Next

Click Finish
After copying th e file, Windows 95 will then detect each of the serial ports in

turn and install them as communications ports.

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 32

Checking the Installation

Using the right-hand mouse button click on the My Computer icon on your
desktop. Click on Properties.

Click on the Device Manager tab

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 33

When the "Device Manager" is viewed th e PCI 1 port Velocity R422/485 card
will appear under the "Multi-function adapters" branch. Also, a Velocity
RS485 Port will appear under the "Ports (COM & LPT) branch".

For most users who have 4 or less COM ports the new port will appear as
COM5 as pi c tur e d above, for use rs with more tha n 5 COM ports t he n e w p ort
will appear as the first available COM ports.

Click for Card Settings
Click for Port Settings

Card Settings

Using the right-hand mouse button click on the My Computer icon on your
desktop. Click on Properties.

Click on the Device Manager tab

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 34

Select the PCI Velocity RS422/485 card from the "Multi-Function Adapter"
entry in Device Manager serial and click on properties to view the cards
general properties.

Click on the Serial Solutions tab Solution s tab produces.

In this window, the COM port assignment may be changed, simply by selecting
a new COM port value from the pull down menu relevant to the port. However,
COM port usage other than those for the PCI Quad Velocity RS422/485 card
itsel f a re not checked, so i t is ad vi s able to fir s t check wh ich COM ports a re in
use - por t availability can be checked by viewing the Device Manager:

All COM ports present will be listed under the entry "Ports (COM & LPT)."
Th e above screens hots ind icat e s that CO M 2 - 4 and COM6 and above are not
installed, and therefore may be used.

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 35

The Maximum Baud Rate Setting for all ports on the card may also be set
from this window. This settting will make the maximum baud rates of all the
ports on this card equal to whatever is set. Individual ports may h ave their
settings changed as shown in Port Settings

Click Here for Port Settings

Port Settings

Using the right-hand mouse button click on the My Computer icon on your
desktop. Click on Properties.

Click on the Device Manager tab

Double clicking on a Velocity RS485 Port entry from the entry "Ports (Com &
LPT)" bra nch in Device Manager will the display general properties window
for the selected p ort (i n th is case COM5).

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 36

Selecting the Port Settings tab produces:

Settings available in this win dow are:
Baud Rate* - deter mines the baud rate at whi ch th e selected port operates, the

maximum value available is dependant upon the Maximum Baud Rate Setting
(see below.)

Data Bits.*
Parity.*
Stop Bits.*
Flow Contr ol *
*These set t i ng s are dependent upon the devic e being used.
Maximum Baud Rate Setting - four val ues are available, which selects th e

maximum baud rate at which the port may operate. The table below, indicates
the ranges of baud rate values available at the Maximum Baud Rate Settings.

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 37

Maximum Baud Rate

115200 230400 460800 921600

50 100 200 400

75 150 300 600
110 220 440 880
150 300 600 1200
300 600 1200 2400
600 1200 2400 4800

1200 2400 4800 9600
1800 3600 7200 1440
2000 4000 8000 16000
2400 4800 9600 19200
3600 7200 14400 28800
4800 9600 19200 38400
7200 14400 28800 57600

9600 19200 38400 76800
19200 38400 76800 153600
38400 76800 153600 230400
57600 115200 230400 460800

115200 230400 460800 921600

Note: Many serial comms applications will not actually register the ports as
ru nning at ba ud r ates of above 115200.

Restore Defa ults - when clicked, resets the selected COM port to the following
values:

Baud Rate: 9600
Data Bits: 8
Parity: None
Stop Bits: 1
Flow Control: Xon / Xoff
Maximum Baud Rate Setting: 115,200

Clicking on the Serial Solutions tab will display:

Settings available in this win dow are:

PCI Quad 422/485 Card Chapter 7 Windows 98/Millenium Installation. • 38

FIFO Sett i ngs.

Enable FIFO - turns the selected ports FIFO buffer on or off. It is strongly

recommended that the FIFO for both por ts is left enabled.
Extend FI FO - when checked, extend s the sel ected port s F I F O bu ffer from 16

to 64 bytes.
Receive Buffer - These settings allow the selection of a receiver FIFO tr igger

setting. Selecting a low value will allow the interrupt to be serviced quicker,
which is good for slow machines. If you have a fast machine, setting a high
value will give you more time for multi-tasking operations.

Transmit Buffer - These s e ttings allo w the se le ctio n o f a transmitter F I F O t rig g er
setting. Selecting a low value w ill send fewer data-byte s p er interrupt, and this is
recommended if you ar e communicating to a slower machine. Selecting a high
value will send more data-bytes per interrupt, and will give more time for multi­tasking operations.

485 Mode offers the options:

Half Duplex / Full Duplex(default) - are used in conjunction with the RS485

Multiplex Jumper Settings.
NOTE: These software settings must match the RS485 Multiplex Jumper

configuration, as described in the section "RS485 Multiplex Jumper Settings"
in Chapter 2, to ensure accurate and error free data transmission.

CTS Hold True, determines wh ether the CTS handshake signal is INPUT from
the ex tern al ser ial devi ce or is permanently forced tru e on th e card. The serial
ports own RTS OUTPUT handshak e sig nals are always taken out to the serial
port connect or.

Restore - when this button is clicked the settings in the current window will be
reset to the default values of:

Enable FIFO: On (C hecked)
Extend FIFO: Off (Unchecked)
Receive Buffer: 3

rd

from left.
Transmit Buffer: 16
485 Mode: Full dupl ex.

PCI Quad 422/485 Card Chapter 8 Windows NT 4.0 Installation. • 39

Chapter 8 Windows NT 4.0
Installation.

Introduction

Microsoft Windows NT Provides built in support for 255 standard serial ports.
To setup your PCI RS422/485 serial card you should follow these steps. Please
note that to change an y kind of hardware configuration under Windows NT you
must be logged in as a user with Administrator level privileges, if you do not
have these please contact your system administrator.

Software Installation.

Insert the PCIQuad Velocity RS422/485 into your PC, as described in chapter 2,
and restart. Place the supplied CDROM titled "Serial Solutions Software" in a
suitable dr ive and from the Start Men u choose Run

Enter <drive>:\diskimg\ssnt\setup (whe re <d riv e>: is the path to the
CDROM drive containing the installation disk).

InstallShield w ill the n install the driv er sof tware auto matically - it will then copy
the necessary files and start itself . This automatically dete cts your new PCI serial
card(s) and does not require any further system restarting.

PCI Quad 422/485 Card Chapter 8 Windows NT 4.0 Installation. • 40

Examining Card Configuration.

Go to Control Panel (Start/Settings/Control Panel)

double click on Serial Solutions PCI

Card Setup

You will be presented with a Serial Solutions PCI Port Con figuration window:

To view the settings of a port, select it and click on settings.

PCI Quad 422/485 Card Chapter 8 Windows NT 4.0 Installation. • 41

Configuring Ports.

Select t he resources ta b:

Settings available in this win dow are:
Settings available in this win dow are:
Baud Rate - determi nes the baud rate at which the selected port operates, the

maximum value available is 921,600 (1 Megabaud.) Note: Many serial comms
applications will not actually register the por ts as runnin g at baud rates of above

115200.

Data Bits.*
Parity.*
Stop Bits.*
Flow Contr ol .*
*Dependent upon device being used.
Advanced - see the section below, titled "Advanced Port Settings."
Restore Defa ults - when clicked, resets the selected COM port to the following

values:

Baud Rate: 9600
Data Bits: 8
Parity: None
Stop Bits: 1
Flow Control: Hardware

PCI Quad 422/485 Card Chapter 8 Windows NT 4.0 Installation. • 42

Advanced Port Settings.

When the Advanced button of Port Settings is selected the following dialogue
is displayed:

Settings available in this win dow are:

FIFO settings.

Receive Trigger Level - These settings allow the selection of a receiver FIFO
trigger setting. Selecting a low value will allow the interrupt to be serviced
quicker, which is good for slow machines. If you have a fast machine, setting a
high value will give you more time for multi-tasking operations.

Software Transmit Limit - These settings allow the selection of a transmitter
FIFO trigger setting. Selecting a low value will send fewer data-bytes per
interrupt, and this is recommended if you are communicating to a slower
machine. Selec ting a high valu e will send more data-bytes per interrupt, and w ill
give mor e time for multi-tasking operations.

FIFO Off - turns the selected ports FIFO buffer on or off. It is strongly
recommended that the FIFO for all ports is left enabled.

485 Mode offers the options:
Half Duplex / Full Duplex(default) - are used in conjunction with the RS485

Multiplex Jumper Settings.
NOTE: These software settings must match the RS485 Multiplex Jumper

configuration, as described in the section "

PCI Quad 422/485 Card Chapter 8 Windows NT 4.0 Installation. • 43

RS485 Multiplex Jumper Settings." in Chapter 2, to ensure accurate and error
free data transmission.

Force CTS True, determines whether the CTS handshake s ig nal is INPUT from
the ex tern al ser ial devi ce or is permanently forced tru e on th e card. The serial
ports own RTS OUTPUT handshak e sig nals are always taken out to the serial
port connect or.

Defaults - When clicked this button resets the advanced properties to th e
followed settings:

FIFO Off: On (u ncheck ed )
Transmit Buffers: 1
Receive Buffers: 8
Use Extended FIFO : Off (Unchecked)
485 Mode: Full Duplex

Uninstalling Serial Solutions PCI.

To uninstall Serial Solutions PCI:
From C ontrol Panel, open the Add /Remove Programs a p plet, then close th e

Control Panel.
Select from the list Serial Solutions PCI.
Click the Add/Remove button.
Windows NT will then uninstall the Serial So lu tions PCI applet witho ut the nee d

for restarting.

PCI Quad 422/485 Card Chapter 9 Windows 2000 Installation • 44

Chapter 9 Windows 2000
Installation

Software Installation

After inserting the PCI card into an available slot and recon n ecting all cables
power up your machine.

The screen shot shown below will appear briefly on your screen.

Insert the Serial Solutions CD ROM into an appropriate drive and click ’Next’.

Select Search for a suitable driver for my device
Click Next

PCI Quad 422/485 Card Chapter 9 Windows 2000 Installation • 45

Select Sp ecify a location
Click Next

In the box under Copy manufacturers files from: type <CDROM
Drive>:\diskimg\sswin2k where <CDROM Drive> is the letter of the drive into
which you inserted the driver CD ROM. Eg. D:\diskimg\sswin2k

Click Next

PCI Quad 422/485 Card Chapter 9 Windows 2000 Installation • 46

Click Yes

Click Finish

The system will then detect the ports br iefly showing the above screen shot.

PCI Quad 422/485 Card Chapter 9 Windows 2000 Installation • 47

Checking your Installation

Using the secondary(Right) mouse button click on the My Computer icon on
your desktop.

Click Properties

Select t he Hardware tab
Click Device Manager

Double Clicking on the Multi-port serial adapters label will display the
name of any installed cards.

Double Clicking on the Ports(COM & LPT) label will display all installed
Ports.

PCI Quad 422/485 Card Chapter 10 Optional RS422/485 Operation • 48

Chapter 10 Optional RS422/485
Operation

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 seco nd, and for distances up to 4000 fe e t the maximum data
rate is 100 Kilobytes per second. A 120-Ohm resistor should be used to terminate th e
receivi ng en d of the line. It is gen erally used between on e transmitter receiver pair to
ONLY one other transmitter receiver pair, but each outp ut can drive up to 10 receivers.

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

D

R

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 tran smit data, the RTS line is used as transmit enable
signal, so p reventing contention between talkers.

RS485 Standard

Up to 32 Driver/ Receiver Pai rs

Line Length Max Data Rate

40 Feet = 12m 10 Mbits/sec

400 Feet = 122m 1 Mbits/sec

4000 Feet = 1219m 100 Kbits/sec

DD

R

R

R

Terminating Impedance’s.

RS422 and RS485 lines should be terminated at the end of the main branch of the
RECEIVER, in th e cables characteristic impedance. These terminating impedance’s
stop ech oes caused by the serial data being reflected ba ck at the cable en d s . It is not
necessary to terminate the transmitter end of the twisted pair.

PCI Quad 422/485 Card Chapter 10 Optional RS422/485 Operation • 49

The AT Dual Port RS422/485, Opto Isolated AT Dual Port RS422/485 and AT Velocity
RS422/485 cards have the correct 120 Ohm (nominal) 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 are automatically
pr ovided by the on board resistors and d o not have to be added by the user.

Fail Safe Open Circuit Detection.

Open circui t is when there ar e no drivers on the circuit . This occurs by design in party
line multi driver/receiver systems and unin tentional ly when the twisted pair lin e is
accidentally cut or disconnected or the transmitting device fails. In RS485 party line
systems there are extended periods of time wh en n one of the many possible talkers are
gated onto the bus. This is known as the line idle state and occurs when all the driver
outputs are in the high imped anc e state. The lines float, perhaps being pulle d to the high
or l ow s tat e by noise or other volta ges on the line.

Without fail safe open circuit detect ion fal se s tart bits are detect ed by the receivers,
either corrupting good communications or causing noise to masquerade as good data.

The on board fail sa fe open cir cu it detection ca u s es the r eceiver to go t o a known, pre­determined state and pr events 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 con n ected together. This
occurs due to either accidental damage to the cable or due to failure of one or more
transmitter/receiver s on the line. The s hort circui t condition is dangerous since damage
to th e receiver m ay occur and communication m ay be corrupt ed or pr evented.

The on boar d fail safe short circuit detection prevents the line impedance from
going to zer o a nd thus protects the in p uts of recei vers an d the outputs of dr ivers.

RS422 Operation.

Generally, in RS422 systems all 8 signal li nes from the 9 pin D connector participate in
the data transfer sequence, thus 4 twisted pair cables are used. One twisted pair carries
the TXD data outwards, one pair brings the RXD data inward, another pair carries the
RTS handshake outwards and the fourth pair brings the CTS handshake inwards. There
is no need to carry the ground from one device to a nother.

This RS422 arrangement allows data to be transmitted and received simultaneousl y
since each signal has its own data cable pair. In addition, the receiver can set RTS t rue
so te lling the transmitter o n its C TS input that the receiver is ready to accept data. In this
way, n o data will ever be transmitted when the receiver is unable to a ccep t it, d u e to a
full input buffer etc. And so no data will be lost.

RS422 Serial Port Cables.

Use screened twisted pair Belden cable 9729 and 9829, L type 2493 and 2919 or IBM
Part No 4716748 cable to make the RS422 connection. Unscreened Belden type 8795
may also be used in less noisy environments.

The on board resist or net wor k s terminat e the r eceiving end of th e twisted pair cable in
its characteristic impedance.

PCI Quad 422/485 Card Chapter 10 Optional RS422/485 Operation • 50

Serial Port 1 To Other PC Cable.

SERIAL PORT 1 Side Other PC SERIAL PO RT Side .
9 Pin Female D Connector 9 Pin Female D Connector

Note:

Receiver ends ter minated in cha racteristic imped ance ONBOARD resist or networks.
USE BELDEN TYPE 9729 etc. see above.
RS485 Gating & Multiplex Jumpers as Factory Set.

RS485 Operation.

The RS485 standard is in t en ded for up to 32 driver receiver pai rs on t he bus. T he line
drivers used in the Serial Solutions RS422/485 card are designed to work correctly in
both RS422 and RS485 systems. The main difference therefore is in how the system is
implemented. Though the card uses a 9 pin D connector , in general, not all the lines are
used for RS485 systems. The RTS+/- and CTS+/- li nes, though driven by the card, are
usually not con nected. In two wire, Half-Duplex configurations the TXD+ line is
connected to the RXD+ whi lst the TXD- l ine is connected to the RXD-, on ly one pair of
twisted wire cable is used in RS485 Half Duplex communications.

The har dware ha ndshaking performed by the CTS+/- and RTS+/- lines in RS422
systems are han dled by a software protocol in RS485 systems. In situa t ions where more
than one device may tran smit data on the shared data line, each cards RTS line is used
as a gating signal to enable the TXD driver only when th at card needs to transmit data,
i.e. s et TXD GAT E or AUTO jumper. This mechanism prevents bus con tention caus ed
by multiple transmitters holding the line in opposing states. Revision 3 and higher
versions of this card have a facility which automatically “gates” the RTS line, thus
enabling the transmitter independently of any software. This “Auto gating” is described
in more detail in the previous 485 half duplex section

The thr ee wi rin g s chemes gi ven descr ibed below are: ­RS485 One Talker Many Listeners (HALF DUPLEX)

RS485 Many Talkers Many Listeners (HALF DUPLEX.)
RS485 Many Talkers Many Listeners (FULL DUPLEX.)

RS485 Cable.

For best noise immunity use twisted pair cables to make the RS485 connection. In Half
Duplex wi rin g only 1 twist ed cable pai r is needed. T wo twi sted pai r cables are n eeded
for Full Duplex communications.

Use screened twisted pair Belden cable 9729 and 9829, UL type 2493 an d 2919 or IBM
Part No 4716748 cable to make the RS485 connection. Termina te the twisted pair cable

PCI Quad 422/485 Card Chapter 10 Optional RS422/485 Operation • 51

at either end in its characteristi c impedan ce, which for the Belden 9729 cable is 120
Ohms. Unscreened Belden type 8795 may also be used in less noisy environments.

RS485 One Talker - Many Listeners, Half Duplex.

There are several schemes for connecting RS485 devices depending on th e
characteristics of the system. In many cases there will be on ly one device, which can
transmit, data and all the others simply listen to it. This scheme is used for theatrical
lightin g i ntensity control in the DMX512 standard. T his is shown below. For the talker
the RS485 TXD GATE jumper should remain in the fac tory set position, i.e. transmitter
is always enabled. There is NO multiplexing of the TXD and RXD lines. Data is only
flowing one way, from PC outwar ds, and is thus a Half-Duplex configuration, only one
twisted pair cable is needed.

Note: Th e Recei ver end of MAI N line termi nated in char acteri s tic impedan ce by
ONBOARD resistor networks, stubs off the main not terminated.

In the above scheme, one RS485 device is talk only, it transmits data, but it does not
receive a ny. Th e ot her RS485 devices are receive on l y, they do not transmit any data at
all.

Half Duplex Settings of RS485 Multiplex

Both jumpers shorted, causing the RXD- & TXD- and the RXD+ & TXD+ signals to
shor t together at the 9 -pin connector.

RS485 Many Talkers- Many Listeners, Half Duplex.

Another popular RS485 layout is for multiple talkers and multiple listeners. This is
shown below. This is also known as "party line" transmission. It is imperative to have
some method of preventin g two devices trying to drive the data lines at the same time.
The normal method is to use the RTS line as a talk enable. The RTS line should go true
immediately prior to the data transmission and go false immediately after the last byte in
the stream is sent.

TXD1+

TXD1-

+TXD n

-TXD n

120

W

-RXD1

+RXD2

120

W

-RXD2
+TXD2

-TXD2

+RXD1

+RXD3

-RXD3
+TXD3

-TXD3

+RXDn-1

-RXDn-1
+TXDn-1

-TXDn-1

-RXDn

+RXDn

Note: BOTH ends of MAIN line terminated in characteristic impedance, stubs off main
line not i mpedance, since both ends receive. The twisted p air ends are wired to both
RXD+ & TXD+ and RXD- & TXD- at each RS485 device!

PCI Quad 422/485 Card Chapter 10 Optional RS422/485 Operation • 52

RS485 Many Talkers- Many Listeners, Full Duplex.

The RS485 many talkers, many listeners, Full Duplex system can be used when all the
RS485 devices have separate Transmit and Receive channels. There is NO multiplexing
of the TX D and RXD signa ls on the same device. This system is especia lly useful wh en
there is no flow control available on the PC, usually due to the use of a third party
communications program that prevents the use of the RTS signal as a "transmit enable"
control, via the TXD GATE jumper. It can be used in the following situations:-

a) The PC is connected to only ONE RS485 device.
b) The PC is communicating with several RS485 devices that are each able to

recognize and respond to their own unique addr ess. The RS485 devices only drive
their TXD lines wh en they are respon din g to requests from the PC to sen d data. In
effect, the RS485 device’s add ress and th e com mand it receives is used to control access
to th e d evices TXD ch ann el.

This is a Full Duplex system. Two twisted pair cables are required. One twisted pair, is
the PC’s TXD channel, it carries the data sent from the PC’s TXD outputs to th e RXD
inputs of each of the RS485 devices. The second twisted pair, is the Devices TXD
channel , it ca rri es t he data sent from each of the d evices’ TXD output s t o the RXD
inputs of the PC.

The advantages of this system are great, s ince n o new communications, s oftwa re is
needed, and the PC can talk and listen at the same time. In effect, the handshaking is
performed by the intelligence of the RS485 devices attached to the PC.

When wired as below, th e PC can transmit data at any time and all the RS485 devices
#1 to #n simu ltaneously receives it.

Only o ne of the RS485 devices may talk, i.e. transmit data, at any one time . Each RS485
device recognizes commands and data addressed to it, it only talks when the PC
commands it to do so. When the RS485 device receives th e com mand to talk from the
PC, it gates its TXD drivers on, sends the data down the device TXD channel, and
disables its TXD drivers. The other RS485 devices remain in t he receive onl y mode
when they ar e not being addressed, they do not transmit any data at all.

RS485 Jumpers, Full Duplex.

Both jumpers l eft unconnected ( not sh orted).

PCI Quad 422/485 Card Chapter 10 Optional RS422/485 Operation • 53

RS485 Full Duplex.

Note: The receiver end of MAIN line terminated in ch aracteristic im p ed ance, s tubs off

the main not terminated.

Optional Grounding Arrangements.

Proper operation of the cable circuit, according to TIA EIA: 485 A (1995) requires
that the cable ground shield is not connected directly to the equipment ground shield. A
current limiting resistor should be used in series with the shield to avoid possible large
current flow due to differences in ground potential. Any one of the methods shown
below can do this.

Configuration A)

GWG

100Ω
(1/2) W

SG

Configuration B)

GWG

SG

SG = Signal Ground Interchange circuit.
GWG = Green wire ground of power system.

= Protective ground of frame ground.

= Circuit ground or circuit

common.

Configuration A) The ci rcui t common of t he eq uipm en t is con n ected t o prot ective g roun d, at one poi nt only by a
100 Ω, ±20% resistor with a power dissipation rating of 1/2W. An additional provision may be made for the resistor to be

bypassed with a strap to connect signal common and protective ground directly together when specific installation
conditions necessitate.

PCI Quad 422/485 Card Index • 54

Index

1

1 Megabaud 6
115200 Baud 32, 43
16450 / 16550 2, 6

4

460800 Baud 32, 43

9

921600 Baud 32, 43

A

asynchronous 6
Autogating 6, 7

B

baud / baud rate 3
BBCARDS.EXE 15, 17, 18
Belden 57
bits 56

buffer 57

Buffer

17

buffer / buffered 2, 3, 6

C

cable 3, 56, 57, 58
CD ROM 52
Changing COM numbers in Windows 95 29, 39
COM 54
command 3, 59
Configuring Ports In Microsoft Windows NT. 45
CTS 2, 6, 56, 57, 58

D

data word length 6
DCD 2
device driver 15, 16
DSR 2
DTR 2

E

emulation 3

F

fail safe 56, 57

FIFO 2, 6

G

gating 58

H

handsh ake 2, 57

I

impedance 56, 57, 58, 59, 61

installation 4, 15
Installing Ports In Microsoft Windows 95 & 98. 23
Installing ports in Windows 3.x 19
interr upts 3

J

jumper 9, 58, 59

L

last 59

loop back 3

M

Maximum Baud Rate 31, 32, 41, 42, 43
Megabaud See 921600 ba ud. See 921600 baud
mode 3, 60

O

open circuit 56

P

parity 3

party line 56, 59

port / ports 2, 3, 4, 6, 15, 45, 56
Port Address 17
protocol 2, 58

R

receive 10, 58, 59, 60
resistor 55, 56, 57, 58

RS232 2, 6, 9
RS422 / RS485 6, 9, 10, 33, 44, 49, 55, 56, 57, 58,

59, 60, 61
RS422 Pinout 8
RS485 Multiplex Jumper Settings 9, 33, 44, 49
RTS 2, 6, 56, 57, 58, 59

RXD 6, 10, 56, 57, 58, 59

PCI Quad 422/485 Card Index • 55

S

serial port 2, 3, 15, 45, 56
shared int errupt 3, 4

short circuit 57

SISR 16
speed 6, 55

T

twisted pair 10, 56, 57, 58, 59
TXD 6, 10, 57, 58, 59, 60

U

Uninstalling Serial Solutions PCI for Windows NT

49

W

Windows 2, 3, 4, 45