Copyright: Copyright © Sealevel Systems, Inc.


Contents

Version Number:  2.5.26

The SeaLINK+232: provides the PC with 1 USB to RS-232 Asynchronous serial port providing a versatile interface for common RS-232 needs (i.e. modem, mouse and plotters). The advantage of this product over more traditional approaches is that it doesn’t require opening the computer case to install nor does it require I/O 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 support.

Installation

Specifications

Technical Description

Troubleshooting

Electrical Interface

Asynchronous Communications

Technical Support

Compliance Notices


Installation

Operating System Installation

There are two(2) basic methods of installation for a Plug and Play device such as a USB I/O adapter. The typical approach is to plug the device in and after receiving the “New Hardware Found” indication, the customer inserts an installation media, i.e. floppy disk or CD,  a driver is located and the installation completes. An alternative method is prior to installing the hardware, the customer runs a “Windows Setup” utility that copies all necessary files to their proper location. When the customer installs the hardware and receives the “New Hardware Found” indication, there is no need to search removable media since all necessary files are already in place on the hard drive. The second approach offers an additional advantage of letting the “Setup” routine install any provided applications.

Both installation methods are supported on the supplied CD, however should you choose the first method, you will still need to run “Setup” and choose the “WinSSD” only option to install the supplied Applications and Help files.

System Installation

The SeaLINK+232: can be connected to any Upstream Type “A” port either at the PC host or an Upstream Hub. The SeaLINK+232 is hot-pluggable meaning there is no need to power down your computer prior to installation. The SeaLINK+232: requires no user hardware configuration since there are no jumpers present on the card.

1.	Connect SeaLINK+232 to Upstream Host or Hub.

This indicates that the system has recognized the new device and will now proceed to locate a driver.

Here you are presented with a choice to have Windows locate the driver or to manually locate the driver yourself. If you have already installed the software by running “Setup”, simply click “Next” to proceed. If you have not yet installed the software, place the installation CD into the drive and then click “Next” to proceed.

Windows has now located a driver and installed the software. Some of the dialog boxes will vary up to this point depending on the installation method used. Click “Finish” to proceed. You should see one more “New Hardware Found”  indication which is the actual port being created.  If you view your systems 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 following:

You can access your new COM: port by using the assigned COM: identifier shown above. In this case, it is COM4 but this assignment will vary from system to system.  At this point, the hardware is functioning and a good next step is to verify it’s proper operation by using the supplied WinSSD diagnostic utility. If you installed the hardware first, you will need to run the SeaCOM Setup utility from the CD and choose the “WinSSD” only option to install the Applications, Help Files, and Samples. After installation, WinSSD can be found in the “SeaCOM” program group.


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 Printed Circuit boards are built to U.L. 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 Heigth	1.0 inches (2.54 cm)


TroubleShooting

Serial Utility test software is supplied with the 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.	Since the SeaLINK+232 USB to RS-232 serial adapter requires no system resources nor does it require any user configuration, the likelihood of installation problems is reduced. If your installation isn’t working, first check to make sure that USB support is enabled in the System BIOS and that 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.	Insure that our software has been installed on the machine so that the necessary files are in place to complete the installation.

3.	When the SeaLINK+232 is configured properly, the USB Enabled LED (EN) will be lit. This should allow you to use WinSSD utility  and the supplied loopback plug to check communications of the device. The supplied loopback plug only connects TD to RD so if you decide to test the Modem Control Signals,  you will need to make a plug that supplies these connections.

4.	When testing the SeaLINK+232 in loopback mode, you should see both the TD and RD LED”s flickering 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 these test pass, then the SeaLINK+232 is ready for use in your application.

5.	If the SeaLINK+232 is enabled and you are able to open the COM: port but can’t seem to make the loopback test pass, then there may be a problem with the RS-232 transceiver on the card. If so, this will require sending the device back to the supplier for repair or replacement.


Technical Description

The SeaLINK+232: 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-232 transceiver supports data rates up to 460.8K baud subject to usual RS-232 cable length limitations.

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)

Name	Pin #	Mode
TD Transmit Data	2	Output
RTS Request To Send	4	Output
DTR Data Term Ready	20	Output
GND Ground	7
RD Receive Data	3	Input
DCD Data Carrier Detect	8	Input
DSR Data Set Ready	6	Input
CTS Clear To Send	5	Input
RI Ring Indicator	22	Input
Note: These assignments meet EIA/TIA/ANSI-574 DTE for DB-25 type connectors.


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.

Figure 1 - 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).


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 wide spread 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 SeaLINK+232: is a DTE device.


Compliance Notices

Federal Communications Commission 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 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

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

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’

EN50082-1 - ‘Electromagnetic compatibility - Generic immunity 	standard’ Part 1 : Residential, commercial and light industry

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.