SeaLevel SeaLINK+485 User manual

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
SeaLINK+485
User Manual | 2102

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Contents
CONTENTS............................................................................................................................................................................................................................2
INTRODUCTION...................................................................................................................................................................................................................3
BEFORE YOU GET STARTED..............................................................................................................................................................................................4
INSTALLATION & CONFIGURATION................................................................................................................................................................................5
CONFIGURATION.................................................................................................................................................................................................................9
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 – COMPLIANCE NOTICES .........................................................................................................................................................................17
WARRANTY ........................................................................................................................................................................................................................18

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Introduction
Overview
The Sealevel Systems SeaLINK+485 equips the PC with 1 USB to RS-530/422/485 Asynchronous serial
port providing a versatile interface for common RS-530/422/485 needs. The advantage of this product over
more traditional approaches is that it doesn’t require opening the computer case, nor does it require
resources such as I/O ports or IRQ’s. It does require a system that supports USB both in terms of hardware
and operating system.

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Before You Get Started
What’s Included
The SeaLINK+485 is shipped with the following items. If any of these items is missing or damaged, contact
the supplier.
•SeaLINK+485 USB to RS-530/422/485 Serial I/O Adapter
•USB Cable Part Number CA179 for Connecting to Upstream Host/Hub
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.

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Installation & Configuration
Software Installation
Windows 98/ME/2000/XP/Vista™ Operating Systems
1. Begin by locating, selecting, and installing the correct software from the Sealevel software driver
database.
2. Select the Part Number (2102) for your device from the listing.
3. Click the ‘Install Drivers’ button.
4. The setup file will automatically detect the operating environment and install the proper
components.
To confirm that the SeaCOM driver has been successfully installed, click on the ‘Start’ button, and then
select ‘All Programs’. You should see the ‘SeaCOM’ program folder listed.
You are now ready to proceed with connecting the 2102 to your system. Refer to the Hardware
Installation section for details.
Windows NT is not USB aware and thus cannot support this
device.

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Physical Installation
The screen captures below are taken from a Windows 98 installation. Your particular operating system
may differ slightly from what is shown based on your version of windows.
The SeaLINK+485: can be connected to any Upstream Type “A” port either at the PC host or an Upstream
Hub. The SeaLINK+485 is hot-pluggable, meaning there is no need to power down your computer prior to
installation. The SeaLINK+485: requires no user hardware configuration since there are no jumpers present
on the card.
1. Connect SeaLINK+485 to an Upstream Host or Hub.
This indicates that the system has recognized the new device and will
now proceed to locate a driver.

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Since you have already installed the software by running “Setup”, simply
click “Next” to proceed. The drivers that were installed during setup will
automatically be used to configure the adapter for use.
Windows has now located a driver and installed the software. After the
driver has been located click “Finish”. You should see one more “New
Hardware Found”, indicating the actual port being created. If you view
your systems Device Manager at this point, you should have a new “COM”
port in the Port (COM & LPT) Device Class. It should look similar to the
screen shot on the following page.

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You can access your new COM: port by using the assigned COM: identifier
shown above. In this case, it is COM5: but this assignment will vary from
system to system. At this point, the hardware is recognized. To verify
operation use Sealevel Systems supplied WinSSD diagnostic utility.
WinSSD can be found in the Start, Programs group.

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Configuration
Electrical Interface Selection
The port on the SeaLINK+485 has the ability to be used as RS-530/422/485, RS-422 or 2 wire RS-485.
This is selectable via the DIP-switch SW1. The chart below describes each of the switch position’s
function. Please refer to the following page for switch setting examples. Switch SW1 ON enables, adds,
and connects. SW1 position OFF disables, removes, and disconnects.
SW1 Function
1RS-485 Two Wire Auto Enable/Disable
2Echo Enable/Disable
3Adds or removes the 120 ohm termination
4
Adds or removes the 1K ohm pull-up resistor in the RS-422/RS-485 receiver circuit
(Receive data only)
5
Adds or removes the 1K ohm pull-down resistor in the RS-422/RS-485 receiver circuit
(Receive data only)
6Connects the TX+ to RX+ for RS-485 two wire operation
7Connects the TX- to RX- for RS-485 two wire operation
8Not Used

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Switch Examples
Please use the following examples to configure your adapter.
ON
1 2 3 4 5 6 7 8
OFF
RS-530/422
OFF
ON
RS-485
1 2 3 4 5 6 7 8
OFF
ON
RS-485
1 2 3 4 5 6 7 8
OFF
Figure 1 – RS-530/422 4 Wire 485 (Default)
Figure 2 – RS-485, 2 Wire with Echo
Figure 3 – RS-485, 2 Wire No Echo

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Technical Description
The SeaLINK+485: utilizes a USB UART. This chip features programmable baud rate, data format, 128 byte
Dual Port TX Buffer, and 384 byte Dual Port RX Buffer. The RS-530/422/485 transceiver supports data rates
up to 921.6K baud.
Features
•Hot-Pluggable device that doesn’t require opening the case
•No system resources are required (i.e., I/O ports or IRQ’s)
•LED status indicators for “USB Enabled”, “TD”, and “RD”
Connector Pin Assignments (DB25 Male)
The SeaLINK+485 complies with the EIA-530 pin out with the following signals supported
Signal
Name
Pin #
Mode
GND
Ground
7
RDB
RX+
Receive Positive
16
Input
RDA
RX-
Receive Negative
3
Input
CTSB
CTS+
Clear To Send Positive
13
Input
CTSA
CTS-
Clear To Send Negative
5
Input
DSRB
DSR+
Data Set Ready Positive
22
Input
DSRA
DSR-
Data Set Ready Negative
6
Input
DCDB
DCD+
Data Carrier Detect Positive
10
Input
DCDA
DCD-
Data Carrier Detect Negative
8
Input
TDB
TX+
Transmit Positive
14
Output
TDA
TX-
Transmit Negative
2
Output
RTSB
RTS+
Request To Send Positive
19
Output
RTSA
RTS-
Request To Send Negative
4
Output
DTRB
DTR+
Data Terminal. Ready
Positive
23
Output
DTRA
DTR-
Data Terminal Ready
Negative
20
Output

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
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
+5 VDC
Rating
50 mA
Mean Time Between Failures (MTBF)
Greater than 150,000 hours. (Calculated)
Physical Dimensions
Package Length 3.8 inches (9.66 cm)
Package Width 2.3 inches (5.84 cm)
Package Height 1.0 inches (2.54 cm)

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Appendix A – Troubleshooting
Serial Utility test software is supplied with the Sealevel Systems adapter and should be used in the
troubleshooting procedures. Using this software and following these simple steps, most common
problems can be eliminated without the need to call Technical Support.
1. If your adapter isn’t working, first check to make sure that USB support is enabled in the System
BIOS and it is functioning properly in the operating system. This can be done by using either the
Windows 98/ME or Windows 2000 Device Manager.
2. Ensure that the Sealevel Systems software has been installed on the machine so that the necessary
files are in place to complete the installation.
3. When the SeaLINK+485 is configured properly, the USB Enabled LED (EN) will be lit. This should
allow you to use Sealevel’s WinSSD utility and the supplied loopback plug to check
communications. The supplied loopback plug connects TD to RD. If you decide to test the Modem
Control Signals, a full pin loopback plug will be required. Details on loopback plugs are included
on WinSSD. Contact Sealevel Systems if you need further assistance.
4. When testing the SeaLINK+485 in loopback mode, you should see both the TD and RD LED”s
flashing as well as seeing echoed data on the screen. The loopback test first transmits a HEX
pattern, 55AA, and then an ASCII string of data. If this test passes, then the SeaLINK+485 is ready
for use in your application.
5. Please note that if the card is configured for 2 wire RS-485 with no echo a loopback test is not
possible. The receiver in this case will be turned off and the test will fail. If you plan on using this
device in two wire mode test the adapter in RS-422 mode first. Then configure the adapter for
your application.
If these steps do not solve your problem, please call Sealevel Systems’ Technical Support, (864) 843-
4343. Our technical support is free and available from 8:00AM-5PM Eastern Time, Monday through
Friday. For email support contact: mailto:[e-mail].

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Appendix B – How To Get Assistance
Please refer to:Appendix A -- Troubleshooting Guide prior to calling Technical Support.
Begin by reading through the Trouble Shooting Guide in Appendix A. If assistance is still
needed, please see below.
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.
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.asp.
Sealevel Systems maintains a web page on the Internet. Our home page address
is www.sealevel.com. The latest software updates, and newest manuals are available via our
web site.
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].
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.

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© Sealevel Systems, Inc. 2102 Manual | SL9090 8/2021
Appendix C – Electrical Interface
RS-530
RS-530 (a.k.a. EIA-530) compatibility means that RS-422 signal levels are met, and the pin-out for the DB-
25 connector is specified. The EIA (Electronic Industry Association) created the RS-530 specification to
detail the pin-out and define a full set of modem control signals that can be used for regulating flow control
and line status. The RS-530 specification defines two types of interface circuits, Data Terminal Equipment
(DTE) and Data Circuit-Terminating Equipment (DCE). The Sealevel Systems adapter is a DTE interface.
RS-422
The RS-422 specification defines the electrical characteristics of balanced voltage digital interface circuits.
RS-422 is a differential interface that defines voltage levels and driver/receiver electrical specifications. On
a differential interface, logic levels are defined by the difference in voltage between a pair of outputs or
inputs. In contrast, a single ended interface, for example RS-232, defines the logic levels as the difference
in voltage between a single signal and a common ground connection. Differential interfaces are typically
more immune to noise or voltage spikes that may occur on the communication lines. Differential interfaces
also have greater drive capabilities that allow for longer cable lengths. RS-422 is rated up to 10 Megabits
per second and can have cabling 4000 feet long. RS-422 also defines driver and receiver electrical
characteristics that will allow 1 driver and up to 32 receivers on the line at once. RS-422 signal levels range
from 0 to +5 volts. RS-422 does not define a physical connector.
RS-485
RS-485 is backwardly compatible with RS-422; however, it is optimized for party line or multi-drop
applications. The output of the RS-422/485 driver is capable of being Active (enabled) or Tri-State
(disabled). This capability allows multiple ports to be connected in a multi-drop bus and selectively polled.
RS-485 allows cable lengths up to 4000 feet and data rates up to 10 Megabits per second. The signal levels
for RS-485 are the same as those defined by RS-422. RS-485 has electrical characteristics that allow for 32
drivers and 32 receivers to be connected to one line. This interface is ideal for multi-drop or network
environments. RS-485 tri-state driver (not dual-state) will allow the electrical presence of the driver to be
removed from the line. Only one driver may be active at a time and the other driver(s) must be tri-stated.
RS-485 can be cabled in two ways, two wire and four wire mode. Two wire mode does not allow for full
duplex communication and requires that data be transferred in only one direction at a time. For half-duplex
operation, the two transmit pins should be connected to the two receive pins (Tx+ to Rx+ and Tx- to Rx-).
Four wire mode allows full duplex data transfers. RS-485 does not define a connector pin-out or a set of
modem control signals. RS-485 does not define a physical connector.

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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 are 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 4 - 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).

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Appendix E – Compliance Notices
Federal Communications Commission (FCC) Statement
This equipment has been tested and found to comply with the limits for Class A 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
commercial environment. 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. Operation of this equipment in a residential
area is likely to cause harmful interference in such case the user will be required to correct
the interference at the user’s expense.
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.

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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 [e-mail]
Trademarks
Sealevel Systems, Incorporated acknowledges that all trademarks referenced in this manual are the service
mark, trademark, or registered trademark of the respective company.