SeaLevel DUOCOM 3088 User manual

DUOCOM™
User Manual | 3088

Contents
CONTENTS...........................................................................................................................................................2
INTRODUCTION ...................................................................................................................................................3
BEFORE YOU GET STARTED ...............................................................................................................................4
CARD SETUP ........................................................................................................................................................6
SOFTWARE INSTALLATION ................................................................................................................................9
HARDWARE INSTALLATION .............................................................................................................................10
TECHNICAL DESCRIPTION ...............................................................................................................................11
SPECIFICATIONS ...............................................................................................................................................12
APPENDIX A –TROUBLESHOOTING................................................................................................................13
APPENDIX B –HOW TO GET ASSISTANCE .....................................................................................................14
APPENDIX C –ELECTRICAL INTERFACE ........................................................................................................15
APPENDIX D –ASYNCHRONOUS COMMUNICATIONS ..................................................................................16
APPENDIX E –SILK-SCREEN ............................................................................................................................17
APPENDIX F –COMPLIANCE NOTICES...........................................................................................................18
WARRANTY ........................................................................................................................................................20

Introduction
The Sealevel Systems DUOCOM:provides the PC with 2 Asynchronous serial ports providing a versatile
interface for common RS-232 needs (i.e., modem, mouse, and plotters).

Before You Get Started
What’s Included
The DUOCOM is shipped with the following items. If any of these items are missing or damaged, please
contact Sealevel for replacement.
•DUOCOM Serial I/O Adapter
Advisory Conventions
Warning
The highest level of importance used to stress a condition where damage could result to the
product, or the user could suffer serious injury.
Important
The middle level of importance used to highlight information that might not seem obvious or a
situation that could cause the product to fail.
Note
The lowest level of importance used to provide background information, additional tips, or other
non-critical facts that will not affect the use of the product.

Factory Default Settings
The DUOCOM factory default settings are as follows:
Port #
Base Address
IRQ
Port 1
280
5
Port 2
288
10
To install the DUOCOM using factory default settings, refer to Installation.
For your reference, record installed DUOCOM settings below:
Port #
Base Address
IRQ

Card Setup
The DUOCOM contains several jumper straps that must be set for proper operation.
Address Selection
Each serial port on the DUOCOM:occupies eight consecutive I/O locations and looks to the PC as a
standard serial port. A DIP switch (SW1) is used to set the port address options for the DUOCOM:. Be careful
when selecting the port addresses as some selections may conflict with existing ports. The following table
shows the addressing options available with the standard PAL. If you do not see an address option that
suits your needs, please contact Sealevel Systems Technical Support about a custom PAL option.
Port1
J2
Port2
J3
SW1
1
SW1
2
SW1
3
SW1
4
3F8
2F8
On
On
On
Off
3E8
2E8
On
On
Off
On
2F8
2E8
On
On
Off
Off
2F8
3E8
On
Off
On
On
3220
3228
On
Off
On
Off
4220
4228
On
Off
Off
On
5220
5228
On
Off
Off
Off
5220
4220
Off
On
On
On
280
290
Off
On
On
Off
300
308
Off
On
Off
On
310
318
Off
On
Off
Off
280
288
Off
Off
On
On
290
298
Off
Off
On
Off
300
280
Off
Off
Off
On
Disabled
Disabled
Off
Off
Off
Off
Figure 1 - Address Selection Table
Each COM: port in your system should have a unique address. Typically, COM1: - COM4: addresses
are 3F8, 2F8, 3E8 & 2E8 Hex. If a COM1: & COM2: are already present, use the second addressing
option, this will provide the typical addresses for COM3: & COM4:
Refer to Appendix A for common address contentions.

Card Setup, Continuing
IRQ Selection
Headers E1 and E2 select the interrupt request for each serial port (E1 - Port 1, E2 - Port 2). If COM1: is
selected, the corresponding jumper must be on the IRQ4 setting. If COM2: is selected, the corresponding
jumper must be on IRQ3.
Most communications software applications default COM3: to IRQ4 and COM4: to IRQ3. This
requires the sharing of interrupts between COM1: and COM3:, and between COM2: and COM4:.
While this is the default, it is not always the preferred setting. Check your software configuration
instructions to determine the most appropriate IRQ selection.
Figure 2 - Header E1 and E2, IRQ Selection
Any two or more ports can share a common IRQ by placing the jumpers on the same IRQ setting and setting
the appropriate selections at E3. Consult your particular software for IRQ selection. If no interrupt is desired,
remove the jumper.
2/9 3 4 5 7 10 11 12 15
2/9 3 4 5 7 10 11 12 15
E2
E1

Card Setup, Continuing
Interrupt Modes
Header E3 selects the interrupt mode for each port. Each port must be set in the correct mode to insure
proper installation.
‘N’ indicates the (N)ormal, single interrupt per port mode. ‘S’ Indicates the (S)hared interrupt mode, which
allows more than one port to access a single IRQ. Any two or more ports can share a common IRQ by
placing the jumpers on the same IRQ setting and setting the appropriate selections at E1. Consult your
particular software for IRQ selection. If no interrupt is desired, remove the jumper. ‘R’ indicates the inclusion
of a 1K ohm pull-down resistor required on one port when sharing interrupts.
Figure 3 - Header E3, Normal IRQ Mode
Set the jumpers to ‘S’ for shared interrupt mode on all blocks sharing an IRQ. Also set one block for ‘R.’ This
provides the pull-down resistor circuit that makes sharing of IRQs possible. If you are using more than one
DUOCOM: or a compatible adapter in a bus you should only have one port set to ‘R.’ The following example
shows both ports sharing a single IRQ.
Figure 4 - Header E3, Shared IRQ Mode
Set the jumper to ‘S’ if you are using more than one DUOCOM: in a bus or you wish to completely remove
the pull-down resistor for hardware compatibility. Setting the adapter in this configuration when it is not
accompanied by a pull-down resistor will prevent the ports from triggering an interrupt.
Figure 5 - Header E3, Sharing IRQ’s with another adapter
1
2
E3
N S R
E3
N S R
1
2
E3
N S R
1
2

Software Installation
Operating System Installation
Do not install the adapter in the machine until the software has been fully installed.
For Windows Users
Begin by locating, selecting, and installing the correct software from the Sealevel software driver database.
1. Select the Part Number (3088) for your device from the listing.
2. Click ‘Download Now’ for the version of SeaCOM compatible with your system.
3. The setup file will automatically detect the operating environment and install the proper
components. Follow the information presented on the installation screens that follow.
4. A screen may appear with the declaration: “The publisher cannot be determined due to the
problems below: Authenticode signature not found.” Please select the ‘Yes’ button and proceed
with the installation. This declaration simply means that the Operating System is not aware of the
driver being loaded. It will not cause any harm to your system.
5. During setup, you may specify installation directories and other preferred configurations. This
program also adds entries to the system registry that are necessary for specifying the operating
parameters for each driver. An uninstall option is included to remove the driver and all registry/INI
file entries from your system.
6. Proceed with the physical installation of your SeaLINK USB serial adapter.
Windows NT is not USB aware and thus cannot support this device.

Hardware Installation
The DUOCOM: can be installed in any of the PC expansion slots, but to access the ‘AT’ or (E)ISA IRQs (10 -
15) it must be installed in one of the 16 bit slots. The DUOCOM: contains several jumper straps for each
port which must be set for proper operation prior to installing the adapter into the computer.
1. Turn off PC power. Disconnect the power cord.
2. Remove the PC case cover.
3. Locate an available slot and remove the blank metal slot cover.
4. Gently insert the DUOCOM: into the slot. Make sure that the adapter is seated properly.
5. Replace the screw.
6. Replace the cover.
7. Connect the power cord.
Installation is complete.

Technical Description
The DUOCOM: utilizes the 16550 UART. This chip features programmable baud rate, data format, interrupt
control and a 16 byte input and output FIFO. Also available as an option is the 16C650 UART that provides
a deeper FIFO (32 bytes) and enhanced clocking features.
Features
•Addressable as COM1: - COM4: and other selectable address combinations.
•‘Shareable’ IRQs allow more than one port to share a single IRQ.
•IRQs 2-5, 7, 10, 11, 12, 15 supported.
Connector Pin Assignments (DB9 Male)
Signal
Name
Pin #
Mode
TD
Transmit Data
3
Output
RTS
Request To Send
7
Output
DTR
Data Term Ready
4
Output
GND
Ground
5
RD
Receive Data
2
Input
DCD
Data Carrier Detect
1
Input
DSR
Data Set Ready
6
Input
CTS
Clear To Send
8
Input
RI
Ring Indicator
9
Input
These assignments meet EIA/TIA/ANSI-574 DTE for DB-9 type connectors.
Please terminate any control signals that are not going to be used. The most common way to do
this is connect RTS to CTS and RI. Also, connect DCD to DTR and DSR. Terminating these pins, if
not used, will help insure you get the best performance from your adapter.

Specifications
Environmental Specifications
Specification
Operating
Storage
Temperature Range
0º to 50º C (32º to 122º F)
-20º to 70º C (-4º to 158º F)
Humidity Range
10 to 90% R.H. Non-Condensing
10 to 90% R.H. Non-Condensing
Manufacturing
All Sealevel Systems Printed Circuit boards are built to UL 94V0 rating and are 100% electrically tested.
These printed circuit boards are solder mask over bare copper or solder mask over tin nickel.
Power Consumption
Supply line
+12 VDC
-12 VDC
+5 VDC
Rating
50 mA
50 mA
195 mA
Mean Time Between Failures (MTBF)
Greater than 150,000 hours. (Calculated)
Physical Dimensions
Board length
5.4 inches (13.72 cm)
Board height including Goldfingers
3.5 inches (8.89 cm)
Board height excluding Goldfingers
3.2 inches (8.13 cm)

Appendix A –Troubleshooting
Serial Utility test software is supplied with the Sealevel Systems adapter and will be used in the
troubleshooting procedures. By using this software and following these simple steps, most common
problems can be eliminated without the need to call Technical Support.
1. Identify all I/O adapters currently installed in your system. This includes your on-board serial ports,
controller cards, sound cards etc. The I/O addresses used by these adapters, as well as the IRQ (if
any) should be identified.
2. Configure your Sealevel Systems adapter so that there is no conflict with currently installed adapters.
No two adapters can occupy the same I/O address.
3. Make sure the Sealevel Systems adapter is using a unique IRQ The IRQ is typically selected via an
on-board header block. Refer to the section on Card Setup for help in choosing an I/O address and
IRQ.
4. Make sure the Sealevel Systems adapter is securely installed in a motherboard slot.
5. When running DOS, Windows 3.x or other operating systems refer to the Serial Utilities software for
that operating system and the User Manual to verify that the Sealevel Systems adapter is configured
correctly. The supplied software contains a diagnostic program 'SSD' that runs under DOS and will
verify if an adapter is configured properly. This diagnostic program is written with the user in mind
and is easy to use. Refer to the DIAG.txt file in the dos\diag directory for detailed instructions on
using 'SSD'.
6. For Windows 95/98 and Windows NT, the diagnostic tool 'WinSSD' is installed in the Sealevel folder
on the Start Menu during the setup process. First find the ports using the Device Manager, then use
'WinSSD' to verify that the ports are functional.
7. Always use the Sealevel Systems diagnostic software when troubleshooting a problem. This will help
eliminate any software issues and identify any hardware conflicts.
8. The following are known I/O conflicts:
•The 278 and 378 settings may conflict with your printer I/O adapter.
•3B0 cannot be used if a Monochrome adapter is installed.
•3F8-3FF is typically reserved for COM1:
•2F8-2FF is typically reserved for COM2:
•3E8-3EF is typically reserved for COM3:
•2E8-2EF is typically reserved for COM4:
If these steps do not solve your problem, please call Sealevel Systems’ Technical Support, [phone].
Our technical support is free and available from 8:00 AM to 5:00 PM Eastern Time Monday through Friday.
For email support contact sup[email protected].

Appendix B –How To Get Assistance
Please refer to Troubleshooting Guide prior to calling Technical Support.
1. Begin by reading through the Troubleshooting Guide in Appendix A. If assistance is still needed
please see below.
2. When calling for technical assistance, please have your user manual and current adapter settings.
If possible, please have the adapter installed in a computer ready to run diagnostics.
3. Sealevel Systems provides an FAQ section on its web site. Please refer to this to answer many
common questions. This section can be found at http://www.sealevel.com/faq.htm .
4. Sealevel Systems maintains a Home page on the Internet. Our home page address is
www.sealevel.com. The latest software updates, and newest manuals are available via our FTP
site that can be accessed from our home page.
5. Technical support is available Monday to Friday from 8:00 a.m. to 5:00 p.m. eastern time. Technical
support can be reached at [phone]. For email support contact sup[email protected]om.
RETURN AUTHORIZATION MUST BE OBTAINED FROM SEALEVEL SYSTEMS BEFORE RETURNED
MERCHANDISE WILL BE ACCEPTED. AUTHORIZATION CAN BE OBTAINED BY CALLING SEALEVEL
SYSTEMS AND REQUESTING A RETURN MERCHANDISE AUTHORIZATION (RMA) NUMBER.

Appendix C –Electrical Interface
RS-232
Quite possibly the most widely used communication standard is RS-232. This implementation has been
defined and revised several times and is often referred to as RS-232 or EIA/TIA-232. The IBM PC computer
defined the RS-232 port on a 9 pin D sub connector and subsequently the EIA/TIA approved this
implementation as the EIA/TIA-574 standard. This standard is defined as the 9-Position Non-Synchronous
Interface between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary
Data Interchange. Both implementations are in widespread use and will be referred to as RS-232 in this
document. RS-232 is capable of operating at data rates up to 20 Kbps at distances less than 50 ft. The
absolute maximum data rate may vary due to line conditions and cable lengths. RS-232 is a single ended
or unbalanced interface, meaning that a single electrical signal is compared to a common signal (ground)
to determine binary logic states. The RS-232 and the EIA/TIA-574 specification define two types of interface
circuits, Data Terminal Equipment (DTE) and Data Circuit-Terminating Equipment (DCE). The DUOCOM: is
a DTE device.

Appendix D –Asynchronous Communications
Serial data communications implies that individual bits of a character are transmitted consecutively to a
receiver that assembles the bits back into a character. Data rate, error checking, handshaking, and
character framing (start/stop bits) are pre-defined and must correspond at both the transmitting and
receiving ends.
Asynchronous communications is the standard means of serial data communication for PC compatibles
and PS/2 computers. The original PC was equipped with a communication or COM: port that was designed
around an 8250 Universal Asynchronous Receiver Transmitter (UART). This device allows asynchronous
serial data to be transferred through a simple and straightforward programming interface. A start bit,
followed by a pre-defined number of data bits (5, 6, 7, or 8) defines character boundaries for asynchronous
communications. The end of the character is defined by the transmission of a pre-defined number of stop
bits (usually 1, 1.5 or 2). An extra bit used for error detection is often appended before the stop bits.
Figure 6 - Asynchronous Communications Bit Diagram
This special bit is called the parity bit. Parity is a simple method of determining if a data bit has been lost
or corrupted during transmission. There are several methods for implementing a parity check to guard
against data corruption. Common methods are called (E)ven Parity or (O)dd Parity. Sometimes parity is not
used to detect errors on the data stream. This is referred to as (N)o parity. Because each bit in
asynchronous communications is sent consecutively, it is easy to generalize asynchronous
communications by stating that each character is wrapped (framed) by pre-defined bits to mark the
beginning and end of the serial transmission of the character. The data rate and communication
parameters for asynchronous communications have to be the same at both the transmitting and receiving
ends. The communication parameters are baud rate, parity, number of data bits per character, and stop bits
(i.e., 9600, N, 8, 1).

Appendix E –Silk-Screen
5.0"
3.9"
4.2"

Appendix F –Compliance Notices
Federal Communications Commission (FCC) Statement
This equipment has been tested and found to comply with the limits for Class B digital
device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in a
residential installation. This equipment generates, uses, and can radiate radio frequency
energy and, if not installed and used in accordance with the instruction manual, may cause
harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by one or
more of the following measures:
•Reorient or relocate the receiving antenna.
•Increase the separation between the equipment and the receiver.
•Connect the equipment into an outlet on a circuit different from that to which the
receiver is connected.
•Consult the dealer or an experienced radio/TV technician for help.
EMC Directive Statement
Products bearing the CE Label fulfill the requirements of the EMC directive (89/336/EEC)
and of the low-voltage directive (73/23/EEC) issued by the European Commission. To obey
these directives, the following European standards must be met:
•EN55022 Class B - “Limits and methods of measurement of radio interference
characteristics of information technology equipment”
•EN55024 –“Information technology equipment Immunity characteristics Limits
and methods of measurement”.
Always use cabling provided with this product if possible. If no cable is provided or if an alternate
cable is required, use high quality shielded cabling to maintain compliance with FCC/EMC directives.

Caution
Sealevel Systems, Inc. is not responsible for any radio or television interference caused by unauthorized
modifications of this equipment or the substitution of attachment of connecting cables and equipment
other than those specified by Sealevel Systems. Such unauthorized modifications, substitutions, or
attachments may void the user’s authority to operate the equipment. The correction of interference caused
by such unauthorized modifications, substitutions, or attachments will be the responsibility of the user.
Always use cabling provided with this product if possible. If no cable is provided or if an alternate cable is
required, use high quality shielded cabling to maintain compliance with FCC directives.
Canadian Radio Interference Regulations
This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment
Regulations.
Cet Appareil numérique de la classe B respecte toutes les exigences de Règlement sur le matériel du
Canada.

Warranty
Sealevel's commitment to providing the best I/O solutions is reflected in the Lifetime Warranty that is
standard on all Sealevel manufactured I/O products. We are able to offer this warranty due to our control
of manufacturing quality and the historically high reliability of our products in the field. Sealevel products
are designed and manufactured at its Liberty, South Carolina facility, allowing direct control over product
development, production, burn-in and testing. Sealevel achieved ISO-9001:2015 certification in 2018.
Warranty Policy
Sealevel Systems, Inc. (hereafter "Sealevel") warrants that the Product shall conform to and perform in
accordance with published technical specifications and shall be free of defects in materials and
workmanship for the warranty period. In the event of failure, Sealevel will repair or replace the product at
Sealevel's sole discretion. Failures resulting from misapplication or misuse of the Product, failure to adhere
to any specifications or instructions, or failure resulting from neglect, abuse, accidents, or acts of nature
are not covered under this warranty.
Warranty service may be obtained by delivering the Product to Sealevel and providing proof of purchase.
Customer agrees to ensure the Product or assume the risk of loss or damage in transit, to prepay shipping
charges to Sealevel, and to use the original shipping container or equivalent. Warranty is valid only for
original purchaser and is not transferable.
This warranty applies to Sealevel manufactured Product. Product purchased through Sealevel but
manufactured by a third party will retain the original manufacturer's warranty.
Non-Warranty Repair/Retest
Products returned due to damage or misuse and Products retested with no problem found are subject to
repair/retest charges. A purchase order or credit card number and authorization must be provided in order
to obtain an RMA (Return Merchandise Authorization) number prior to returning Product.
How to obtain an RMA (Return Merchandise Authorization)
If you need to return a product for warranty or non-warranty repair, you must first obtain an RMA number.
Please contact Sealevel Systems, Inc. Technical Support for assistance:
Available Monday –Friday, 8:00AM to 5:00PM EST
Phone [phone]
Email [email protected]
Trademarks
Sealevel Systems, Incorporated acknowledges that all trademarks referenced in this manual are the service
mark, trademark, or registered trademark of the respective company.