SEALEVEL 2104 SEALINK+485I USB Serial Interface Adapter User Manual
- June 5, 2024
- SEALEVEL
Table of Contents
User Manual 2104
Introduction
Overview
The Sealevel Systems SeaLINK+485I equips the PC with 1 isolated USB to
RS-422/485 Asynchronous serial port providing a versatile interface for common
RS-422/485 needs. The SeaLINK+485I connects through the PC’s external USB
port, so it does not require opening the computer case. Resources such as
IRQ’s and I/O addresses are also not utilized. It does require a system that
supports USB in hardware and operating system.
Before You Get Started
What’s Included
The SeaLINK+485I is shipped with the following items. If any of these items
are missing or damaged, contact the supplier.
- SeaLINK+485I Isolated USB to RS-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 is 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 is 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 is used to provide background information,
additional tips, or other non-critical facts that will not affect the use of
the product.
Installation
Operating System Installation
Windows Installation
Do not install the Adapter in the machine until the software has been fully installed.
Only users running Windows 7 or newer should utilize these instructions for accessing and installing the appropriate driver via Sealevel’s website. If you are utilizing an operating system prior to Windows 7, please contact Sealevel by calling 864.843.4343 or emailing support@sealevel.com to receive access to the proper driver download and installation instructions.
- Begin by locating, selecting, and installing the correct software from the Sealevel software driver database.
- Type in or select the part number (#2104) for the adapter from the listing.
- Select “Download Now” for SeaCOM for Windows.
- SeaCOM software can also be downloaded from the 2104-product webpage: SeaLINK+485I Product
- The setup files will automatically detect the operating environment and install the proper components. Follow the information presented on the screens that follow.
- A screen may appear with text similar to: “The publisher cannot be determined due to the problems below: Authenticode signature not found.” Please click the ‘Yes’ button and proceed with the installation. This declaration simply means that the operating system is not aware of the driver is loaded. It will not cause any harm to your system.
- During setup, the user 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 also included to remove all registry/INI file entries from the system.
- The software is now installed, and you can proceed with the hardware installation.
Linux Installation
You MUST have “root” privileges to install the software and drivers.
The syntax is case-sensitive.
SeaCOM for Linux can be downloaded here: https://www.sealevel.com/support
/software-seacom-linux/. It includes the README and the Serial-HOWTO help
files (located at seacom/dox/howto). This series of files both explains
typical Linux serial implementations and informs the user about Linux syntax
and preferred practices.
User can use a program such as 7-Zip to extract the tar.gz file.
In addition, the software selectable interface settings can be accessed by
referencing season/utilities/2104mode. For additional software support,
including QNX, please call Sealevel Systems’ Technical Support, (864) 8434343.
Our technical support is free and available from 8:00 AM – 5:00 PM Eastern
Time, Monday through Friday. For email support contact:
support@sealevel.com.
You are now ready to proceed with connecting 2104 to your system. Refer to the
Hardware Installation section for details.
Windows NT is not USB aware and thus cannot support this device.
Hardware Installation
The screen captures below are taken from a Windows 7 installation. Your
particular operating system may differ slightly from what is shown based on
your version of windows.
The SeaLINK+485I can be connected to any Upstream Type “A” port either at the
PC host or an Upstream Hub. The SeaLINK+485I is hot-pluggable, meaning there
is no need to power down your computer prior to installation. The SeaLINK+485I
has an onboard 8-position dip switch that is used to configure the interface.
Prior to connecting the SeaLINK+485I, be sure to configure this dip switch for
your specific application. Please see the Configuration section for more
information. The SeaLINK+485I defaults to RS-422 mode so changes are only
required if you will be using the product in an RS-485 application.
- After installing the software connect SeaLINK+485I to an Upstream Host or Hub.
This indicates that the system has recognized the new device and will now proceed to locate and automatically install the driver.
This window indicates that the device has been successfully installed. You may see these windows appear as a balloon in the bottom right corner of your desktop momentarily instead of as a window. If you view your system’s Device Manager at this point, you should have a new “COM” port in the Ports (COM & LPT) Device, Class. It should look similar to the screenshot on the following page.
HARDWARE INSTALLATION, CONTINUED
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. wind can be found in the Start Menu under the SeaCOM group.
Configuration
Electrical Interface Selection
The port on the SeaLINK+485I has the ability to be used in both half and full
duplex RS-422/485 applications. This is selectable through DIP-switch SW1. The
chart below describes each switch position function. Please refer to the
following page for switch setting examples. Switch SW1, in the “ON” position,
either enable, adds, or connects, based on the function of the switch position
listed below. Switch SW1, position OFF, disables, remove, or disconnect.
SW1 | Function |
---|---|
1 | RS-485 Two Wire Auto Enable/Disable |
2 | Echo Enable/Disable |
3 | Adds 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)
6| Connects the TX+ to RX+ for RS-485 two-wire operation
7| Connects the TX- to RX- for RS-485 two-wire operation
8| Not Used
CONFIGURATION, CONTINUED
Switch Examples
Please use the following examples to configure your adapter.
Figure 2 is the first RS-485 picture: 1 ON, 2 off, 3 ON, 4 ON, 5 ON, 6 ON, 7
ON, and 8 off.
Figure 3 is the second RS-485 picture: 1 ON, 2 ON, 3 ON, 4 ON, 5 ON, 6 ON, 7
ON, and 8 off.
Technical Description
The SeaLINK+485I: utilizes a USB UART. This chip features a programmable baud rate, data format, 128byte Dual Port RX Buffer, and 256-byte Dual Port TX Buffer. The RS-422/485 transceiver supports data rates from 300 baud up to 921.6K baud.
Features
- Hot-Pluggable device
- Does not 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+485I 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 |
TDB | TX+ | Transmit Positive | 14 | Output |
TDA | TX- | Transmit Negative | 2 | Output |
The modem control signals are internally biased as follows: RTS is connected to CTS, DTR is connected to DCD and DSR, and RI is tied inactive.
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 | 100 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) |
Appendix A – Troubleshooting
The adapter should provide years of trouble-free service. However, in the event that the device appears to not be functioning incorrectly, the following tips can eliminate the most common problems without the need to call Technical Support.
-
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. -
Ensure that the Sealevel Systems software has been installed on the machine so that the necessary files are in place to complete the installation.
-
When the SeaLINK+485I 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 within WinSSD. Contact Sealevel Systems if you need further assistance. -
When testing the SeaLINK+485I in loopback mode, you should see both the TD and RD LED 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+485I is ready for use in your application.
-
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
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, at 864-843-4343. Our technical support is free and available from 8:00 A.M.- 5:00 P.M. Eastern Time Monday through Friday. For email support contact support@sealevel.com.
Appendix B – How To Get Assistance
Please refer to 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 on a computer ready to run diagnostics.
- Sealevel Systems provides an FAQ section on its website. 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 website.
- 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 864-843-4343.
RETURN AUTHORIZATION MUST BE OBTAINED FROM SEA LEVEL 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-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 of 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 modes.
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.
Appendix D – Ground Loop Phenomenon
What is Ground Loop?
The ground loop Phenomenon occurs when two (or more) pieces of equipment are
connected with a common ground and a different ground potential exists at each
location. This current can cause the connected equipment to experience noise
that in turn causes data transmission errors. In the extreme, this ground
current can cause equipment malfunction or even destruction.
Cabling Recommendations
When connecting the SeaLINK+485I in an RS-485 network, care should be taken
that both ends of the network are not isolated from the ground (see Figure 4).
This “floating” ground condition could cause capacitive or inductive coupling
of voltages that will cause a breakdown in the DC to DC converter circuit or
in the optoisolator circuit. This condition will cause data errors and
possibly the destruction of the receiver circuit.
Appendix E – Asynchronous Communications
Serial data communications imply that individual bits of a character are
transmitted consecutively to a receiver that assembles the bits back into a
character. The 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.
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 in 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 must 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 F – Silk-Screen
Appendix G – 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.
This is a Class B Product. In a domestic environment, this product may cause
radio interference in which case the user may be required to take adequate
measures to prevent or correct the interference.
Always use the 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.
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 | 864-843-4343 |
support@sealevel.com |
Trademarks
Sealevel Systems, Incorporated acknowledges that all trademarks referenced in
this manual are the service mark, trademark, or registered trademark of the
respective company.
© Sealevel Systems, Inc. 2104 Manual | SL9092 9/2021
Documents / Resources
|
SEALEVEL 2104 SEALINK+485I USB Serial Interface
Adapter
[pdf] User Manual
2104, SEALINK 485I USB Serial Interface Adapter, 2104 SEALINK 485I USB Serial
Interface Adapter, USB Serial Interface Adapter, Serial Interface Adapter,
Interface Adapter, Adapter
---|---
References
- FAQs - Sealevel
- Sign in to your account
- USB to 1-Port Isolated RS-422, RS-485, RS-530 DB25 Serial Interface Adapter - Sealevel
- Software: SeaCOM - Linux - Sealevel
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