SeaLevel SeaLINK+ 485 User manual

Part # 2102
Sealevel Systems, Inc
155 Technology Place
P.O. Box 830
Liberty, SC 29657 USA
Phone: [phone]
FAX: [phone]
www.sealevel.com
SeaLINK+485
USER MANUAL
TM

Contents
INTRODUCTION ........................................................................ 1
OVERVIEW ...........................................................................................1
WHAT’S INCLUDED..............................................................................1
INSTALLATION.......................................................................... 2
OPERATING SYSTEM INSTALLATION ....................................................2
SYSTEM INSTALLATION .......................................................................2
CONFIGURATION...................................................................... 6
ELECTRICAL INTERFACE SELECTION.....................................................6
SWITCH EXAMPLES .............................................................................7
TECHNICAL DESCRIPTION ....................................................... 8
FEATURES............................................................................................8
CONNECTOR PIN ASSIGNMENTS (DB25 MALE)..................................8
SPECIFICATIONS....................................................................... 9
ENVIRONMENTAL SPECIFICATIONS.......................................................9
MANUFACTURING................................................................................9
POWER CONSUMPTION........................................................................9
MEAN TIME BETWEEN FAILURES (MTBF)..........................................9
PHYSICAL DIMENSIONS........................................................................9
APPENDIX A -TROUBLESHOOTING....................................... 10
APPENDIX B -HOW TO GET ASSISTANCE............................. 11
APPENDIX C -ELECTRICAL INTERFACE................................ 12
RS-530.............................................................................................12
RS-422.............................................................................................12
RS-485.............................................................................................13
APPENDIX D -ASYNCHRONOUS COMMUNICATIONS ............ 14
APPENDIX E -COMPLIANCE NOTICES................................... 15
FEDERAL COMMUNICATIONS COMMISSION STATEMENT...................15
EMC DIRECTIVE STATEMENT ...........................................................15

WARRANTY............................................................................ 16
Figures:
Figure 1-RS-530/422 4 Wire 485 (Default)....................................................7
Figure 2 -RS-485, 2 Wire with Echo ...............................................................7
Figure 3 -RS-485, 2 Wire No Echo.................................................................7
Figure 4 -Asynchronous Communications Bit Diagram...............................14
© 2001c Sealevel Systems, Incorporated. All rights reserved.

Introduction
Sealevel Systems SeaLINK+485 Page 1
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.
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
•Sealevel Software

Installation
Sealevel Systems SeaLINK+485 Page 2
Installation
Operating System Installation
Choose Install Software at the beginning of the CD and select the Serial I/O
software drivers and install SeaCOM.
System 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.

Installation
Sealevel Systems SeaLINK+485 Page 3
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.

Installation
Sealevel Systems SeaLINK+485 Page 4
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.

Installation
Sealevel Systems SeaLINK+485 Page 5
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.

Configuration
Sealevel Systems SeaLINK+485 Page 6
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
4Adds or removes the 1K ohm pull-up resistor in the RS-422/RS-485 receiver circuit (Receive data only)
5Adds 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

Configuration
Sealevel Systems SeaLINK+485 Page 7
Switch Examples
Please use the following examples to configure your adapter.
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
ON
1 2 3 4 5 6 7 8
OFF
RS-530/422
ON
RS-485 1 2 3 4 5 6 7 8
OFF
OFF
ON
RS-485 1 2 3 4 5 6 7 8
OFF

Technical Description
Sealevel Systems SeaLINK+485 Page 8
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 3Input
CTSB CTS+ Clear To Send Positive 13 Input
CTSA CTS-Clear To Send Negative 5Input
DSRB DSR+ Data Set Ready Positive 22 Input
DSRA DSR-Data Set Ready Negative 6Input
DCDB DCD+ Data Carrier Detect Positive 10 Input
DCDA DCD-Data Carrier Detect Negative 8Input
TDB TX+ Transmit Positive 14 Output
TDA TX-Transmit Negative 2Output
RTSB RTS+ Request To Send Positive 19 Output
RTSA RTS-Request To Send Negative 4Output
DTRB DTR+ Data Terminal. Ready Positive 23 Output
DTRA DTR-Data Terminal Ready Negative 20 Output

Specifications
Sealevel Systems SeaLINK+485 Page 9
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)

Appendix A –Troubleshooting
Sealevel Systems SeaLINK+485 Page 10
Appendix A -Troubleshooting
Serial Utility test software is supplied with the Sealevel Systems adapter and
will 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 a 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.

Appendix B –How To Get Assistance
Sealevel Systems SeaLINK+485 Page 11
Appendix B -How To Get Assistance
1. Read this manual thoroughly before attempting to install the
adapter in your system.
2. When calling for technical assistance, please have your user
manual and current adapter settings. If possible, please have the
adapter connected in a computer ready to run diagnostics.
3. Sealevel Systems provides an FAQ section on its web site. Please
refer to this for many commonly asked questions. This section
can be found at http://www.sealevel.com/faq.htm .
4. Visit Sealevel’s website at www.sealevel.com for the latest
software updates and newest manuals.
5. Technical support is available Monday through 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.

Appendix C -Electrical Interface
Sealevel Systems SeaLINK+485 Page 12
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.

Appendix C -Electrical Interface
Sealevel Systems SeaLINK+485 Page 13
RS-485
RS-485 is backwardly compatible with RS-422; however, it is optimized for
partyline 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.

Appendix D -Asynchronous Communications
Sealevel Systems SeaLINK+485 Page 14
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. Character boundaries for asynchronous
communications are defined by a starting bit followed by a pre-defined number
of data bits (5, 6, 7, or 8). 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.
Remain Idle or
next start bit
Odd, Even
or
Unused
STOP
P
BIT
5 to 8 Data Bits
Idle state of
line
1
0
1
1.5
2
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 refereed 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 -Compliance Notices
Sealevel Systems SeaLINK+485 Page 15
Appendix E -Compliance Notices
Federal Communications Commission Statement
FCC -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 his own 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.
EN60950 (IEC950) -‘Safety of information technology
equipment, including electrical business equipment’
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 EMC directives.

Warranty
Sealevel Systems SeaLINK+485 Page 16
Warranty
Sealevel Systems, Inc. provides a lifetime warranty for this product. Should this
product fail to be in good working order at any time during this period, Sealevel
Systems will, at it's option, replace or repair it at no additional charge except as
set forth in the following terms. This warranty does not apply to products
damaged by misuse, modifications, accident or disaster.
Sealevel Systems assumes no liability for any damages, lost profits, lost
savings or any other incidental or consequential damage resulting from the use,
misuse of, or inability to use this product. Sealevel Systems will not be liable
for any claim made by any other related party.
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.
Sealevel Systems, Incorporated
155 Technology Place
P.O. Box 830
Liberty, SC 29657 USA
[phone] FAX: [phone]
www.sealevel.com
email: [email protected]
Technical Support is available from 8 a.m. to 5 p.m. Eastern time.
Monday -Friday
Trademarks
Sealevel Systems, Incorporated acknowledges that all trademarks referenced in
this manual are the service mark, trademark, or registered trademark of the
respective company.
SeaLINK+485 is a trademark of Sealevel Systems, Incorporated.