CyberResearch COMHP 7404 User manual

®
Serial Communications
COMHP 7404/-D25
PCI 4-Port Serial Interface Card,
460.8 kbps Data Rate, 128-Byte
FIFO Buffer, with 4 DB-9M Cable
or 4 DB-25M Cable (-D25 Model)
USER’S MANUAL
VER. 2.0C• Jun-10
No part of this manual may be reproduced without permission
CyberResearch®,Inc.
Hwww.cyberresearch.com
25 Business Park Dr., Branford, CT 06405 USA
203-643-5000 (9 A.M. to 5 P.M. EST) FAX: [phone]

CyberResearch® Serial Communications COMHP 7404/-D25
©Copyright 2010
All Rights Reserved.
June 9, 2010
The information in this document is subject to change without prior notice in order
to improve reliability, design, and function and does not represent a commitment
on the part of CyberResearch, Inc.
In no event will CyberResearch, Inc. be liable for direct, indirect, special,
incidental, or consequential damages arising out of the use of or inability to use
the product or documentation, even if advised of the possibility of such damages.
This document contains proprietary information protected by copyright. All rights
are reserved. No part of this manual may be reproduced by any mechanical,
electronic, or other means in any form without prior written permission of
CyberResearch, Inc.
Trademarks
“CyberResearch,” and “COMHP 7404/-D25,” are trademarks of CyberResearch,
Inc. Other product names mentioned herein are used for identification purposes
only and may be trademarks and/or registered trademarks of their respective
companies.
• NOTICE •
CyberResearch, Inc. does not authorize any CyberResearch product for use in life
support systems, medical equipment, and/or medical devices without the written
approval of the President of CyberResearch, Inc. Life support devices and
systems are devices or systems which are intended for surgical implantation into
the body, or to support or sustain life and whose failure to perform can be
reasonably expected to result in injury. Other medical equipment includes devices
used for monitoring, data acquisition, modification, or notification purposes in
relation to life support, life sustaining, or vital statistic recording. CyberResearch
products are not designed with the components required, are not subject to the
testing required, and are not submitted to the certification required to ensure a
level of reliability appropriate for the treatment and diagnosis of humans.
CyberResearch, Inc. iii
25 Business Park Drive P: [phone]; F: [phone]
Branford, CT USA www.cyberresearch.com

COMHP 7404/-D25 CyberResearch® Serial Communications
Revision History
Revision # Description Date of Issue
1.0 Initial Release May 1, 2007
2.0C Revision June 9, 2010
iv ©Copyright 2010 CyberResearch, Inc.

CyberResearch® Serial Communications COMHP 7404/-D25
CyberResearch, Inc. v
25 Business Park Drive P: [phone]; F: [phone]
Branford, CT USA www.cyberresearch.com
Table of Contents
INTRODUCTION............................................................................................................................................1
OVERVIEW .....................................................................................................................................................................1
WHAT’S INCLUDED ........................................................................................................................................................1
FACTORY DEFAULT SETTINGS........................................................................................................................................1
CARD SETUP ................................................................................................................................................2
RS-485 ENABLE MODES ................................................................................................................................................2
Interface Mode Examples SW1 – SW4 (continued) ..................................................................................................4
ADDRESS AND IRQ SELECTION ......................................................................................................................................4
ELECTRICAL INTERFACE SELECTION..............................................................................................................................5
CLOCK MODES...............................................................................................................................................................6
BAUD RATES AND DIVISORS FOR THE ‘DIV1’ MODE......................................................................................................6
INSTALLATION.............................................................................................................................................7
OPERATING SYSTEM INSTALLATION ..............................................................................................................................7
For Windows Users....................................................................................................................................................7
Other Operating Systems............................................................................................................................................7
SYSTEM INSTALLATION..................................................................................................................................................7
TECHNICAL DESCRIPTION...........................................................................................................................8
CONNECTOR PIN ASSIGNMENTS.....................................................................................................................................8
RS-422/485 (DB 9 Male)........................................................................................................................................8
RS-232 (DB-9 Male) ..............................................................................................................................................8
CONNECTOR PIN ASSIGNMENTS.....................................................................................................................................9
RS-232, RS-422/485 (DB-37 Male).......................................................................................................................9
SPECIFICATIONS ........................................................................................................................................10
ENVIRONMENTAL SPECIFICATIONS...............................................................................................................................10
MANUFACTURING ........................................................................................................................................................10
POWER CONSUMPTION .................................................................................................................................................10
MEAN TIME BETWEEN FAILURES (MTBF)...................................................................................................................10
PHYSICAL DIMENSIONS................................................................................................................................................10
APPENDIX A-TROUBLESHOOTING...........................................................................................................11
APPENDIX B-ELECTRICAL INTERFACE...................................................................................................12
RS-232.........................................................................................................................................................................12
RS-422.........................................................................................................................................................................12
RS-485.........................................................................................................................................................................13
APPENDIX C- ASYNCHRONOUS COMMUNICATIONS.................................................................................14
APPENDIX D-SILK-SCREEN .....................................................................................................................15
APPENDIX E-COMPLIANCE NOTICES......................................................................................................16
FEDERAL COMMUNICATIONS COMMISSION STATEMENT..............................................................................................16
EMC DIRECTIVE STATEMENT ......................................................................................................................................16

COMHP 7404/-D25 CyberResearch® Serial Communications
vi ©Copyright 2010 CyberResearch, Inc.
TABLE OF FIGURES
Figure 1- Switches SW1- SW4, RS-422..................................................................................................................................3
Figure 2 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘No Echo’ and the termination resistor in circuit.........3
Figure 3 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘Echo’ and no termination resistor in circuit................3
Figure 4 - Switches SW1- SW4, RS-485 ‘RTS’ Enabled, with ‘No Echo’ and no termination resistor in circuit. .........4
Figure 5 - Switches SW1- SW4, RS-485 ‘RTS’ Enabled, with ‘Echo’ and no termination resistor in circuit. ...............4
Figure 6 - Asynchronous Communications Bit Diagram...................................................................................................14

CyberResearch® Serial Communications COMHP 7404/-D25
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Introduction
Overview
The CyberResearch®COMHP 7404 is a four channel RS-232/485/422 PCI Bus serial I/O adapter supporting data rates up to
460.8K bps.
The RS-232 compatibility allows for connection to devices utilizing the RS-232 electrical interface, such as modems,
data-entry terminals, and plotters.
RS-422 provides excellent communications for long distance device connections up to 4000ft., where noise immunity and
high data integrity are essential.
RS-485 is optimized for ‘Multi-Drop’ or ‘Party-line’ operations selecting data from multiple peripherals (as many as 31
devices can be connected on an RS-485 bus).
In both RS-485 and RS-422 modes, the card works seamlessly with the standard operating system serial driver. In RS-485
mode, our special auto-enable feature allows the RS-485 ports to be viewed by the operating system as a COM: port. This
allows the standard COM: driver to be utilized for RS-485 communications. Our on-board hardware automatically handles
the RS-485 driver enable.
A quadracable splits the DB-37 connector on the backplate of the CyberResearch Adapter into four separate cables. On the
COMHP 7404, these four cables terminate in DB-9M connectors. On the COMHP 7404-D25, these four cables terminate in
DB-25M connectors.
What’s Included
The COMHP 7404 is shipped with the following items. If any of these items is missing or damaged, contact CyberResearch,
Inc.
•COMHP 7404 Serial I/O Adapter
•SeaCOM Software
•Quadracable Cable providing 4 DB-9 connectors (COMHP 7404)
•Quadracable Cable providing 4 DB-25 connectors (COMHP 7404-D25)
Factory Default Settings
The COMHP 7404 factory default settings are as follows:
Port # Clock DIV Mode Enable Mode
Port 1 4 RS-422
Port 2 4 RS-422
Port 3 4 RS-422
Port 4 4 RS-422
To install the COMHP 7404 using factory default settings, refer to Installation on page 7.

COMHP 7404/-D25 CyberResearch® Serial Communications
2©Copyright 2010 CyberResearch, Inc.
Card Setup
RS-485 Enable Modes
RS-485 is ideal for multi-drop or network environments. RS-485 requires a tri-state driver that will allow the electrical
presence of the driver to be removed from the line. The driver is in a tri-state or high impedance condition when this occurs.
Only one driver may be active at a time and the other driver(s) must be tri-stated. The output modem control signal Request
To Send (RTS) is typically used to control the state of the driver. Some communication software packages refer to RS-485 as
RTS enable or RTS block mode transfer.
One of the unique features of the COMHP 7404 is the ability to be RS-485 compatible without the need for special software
or drivers. This ability is especially useful in Windows and other protected mode environments where the lower level I/O
control is abstracted from the application program. This ability means that the user can effectively use the COMHP 7404 in
an RS-485 application with existing (i.e. standard RS-232) software drivers.
Switches SW1 - SW4 are used to control the RS-485 mode functions for the driver circuit. The selections are ‘RTS’ enable
(silk-screen ‘RT’) or ‘Auto’ enable (silk-screen ‘AT’). The ‘Auto’ enable feature automatically enables/disables the RS-485
interface. The ‘RTS’ mode uses the ‘RTS’ modem control signal to enable the RS-485 interface and provides backward
compatibility with existing software products.
Position 3 (silk-screen ‘NE’) of these switches is used to control the RS-485 enable/disable functions for the receiver circuit
and determine the state of the RS-422/485 driver. The RS-485 ‘Echo’ is the result of connecting the receiver inputs to the
transmitter outputs. Every time a character is transmitted; it is also received. This can be beneficial if the software can handle
echoing (i.e. using received characters to throttle the transmitter) or it can confuse the system if the software does not. To
select the ‘No Echo’ mode select silk-screen position ‘NE’.
Typically, each end of the RS-485 bus must have a line-terminating resistor (RS-422 terminates the receive end only). A
120-ohm resistor is across each RS-422/485 input in addition to a 1K-ohm pull-up/pull-down combination that biases the
receiver inputs. Only the ends of an RS-485 network should have the 120-Ohm terminating resistor. Position 4 (silk-screen
‘T’) selects the presence of the 120-Ohm termination resistor across the input data pins (RX+/RX-). To add the termination
select the ‘On’ position, to remove it select the ‘Off’ position.
For RS-422/530/449 compatibility set all switches ‘Off’. Examples on the following pages describe some of the valid
settings for SW1-SW4.

CyberResearch® Serial Communications COMHP 7404/-D25
Interface Mode Examples SW1 – SW4
1 2 3 4
ON
OFF
AT RT NE T
Figure 1- Switches SW1- SW4, RS-422
1 2 3 4
ON
OFF
AT RT NE T
Figure 2 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘No Echo’ and the termination resistor in circuit.
1 2 3 4
ON
OFF
AT RT NE T
Figure 3 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘Echo’ and no termination resistor in circuit.
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COMHP 7404/-D25 CyberResearch® Serial Communications
Interface Mode Examples SW1 – SW4 (continued)
1 2 3 4
ON
OFF
AT RT NE T
Figure 4 - Switches SW1- SW4, RS-485 ‘RTS’ Enabled, with ‘No Echo’ and no termination resistor in circuit.
1 2 3 4
ON
OFF
AT RT NE T
Figure 5 - Switches SW1- SW4, RS-485 ‘RTS’ Enabled, with ‘Echo’ and no termination resistor in circuit.
Address and IRQ selection
The COMHP 7404 is automatically assigned resources by your motherboard BIOS. Only the I/O addresses may be modified
by the user. Adding or removing other hardware may change the assignment of I/O addresses and IRQs.
4©Copyright 2010 CyberResearch, Inc.