United Kingdom:One Omega Drive, River Bend Technology Centre
ISO 9002 CertifiedNorthbank, Irlam, Manchester
M44 5BD United Kingdom
TEL: +44 (0)161 777 6611FAX: +44 (0)161 777 6622
Toll Free in United Kingdom: 0800-488-488
e-mail: sales@omega.co.uk
OMEGAnet®Online Service Internet e-mail
www.omega.com info@omega.com
It is the policy of OMEGA to comply with all worldwide safety and EMC/EMI regulations that
apply. OMEGA is constantly pursuing certification of its products to the European New Approach
Directives. OMEGA will add the CE mark to every appropriate device upon certification.
The information contained in this document is believed to be correct, but OMEGA Engineering, Inc. accepts
no liability for any errors it contains, and reserves the right to alter specifications without notice.
WARNING: These products are not designed for use in, and should not be used for, patient-connected applications.
The Omega Engineering OMG-COMM+232.PCI is a two channel PCI Bus serial
I/O adapter for the PC and compatibles. It provides two RS-232 serial ports
supporting data rates up to 460.8K bps.
The OMG-COMM+232.PCI works seamlessly with the standard operating
system serial driver. UART upgrades are available providing 32 and 64 byte
FIFOs.
What’s Included
The OMG-COMM+232.PCI is shipped with the following items. If any of these
items are missing or damaged, contact the supplier.
• OMG-COMM+232.PCI Serial I/O Adapter
• Serial Utility Software
• User Manual
Factory Default Settings
The OMG-COMM+232.PCI factory default settings are as follows:
Port # Clock Mode
Port 1 DIV4
Port 2 DIV4
To install the OMG-COMM+232.PCI using factory default settings, refer to
Installation on page 7.
For your reference, record installed OMG-COMM+232.PCI settings below:
Port # Clock Mode
Port 1
Port 2
Omega Engineering COMM+232.PCI Page 1
Card Setup
Card Setup
Address and IRQ selection
The OMG-COMM+232.PCI is automatically assigned I/O addresses and IRQs
by your motherboard BIOS. Only the I/O address may be modified by the user.
Adding or removing other hardware may change the assignment of I/O
addresses and IRQs.
Clock Modes
The OMG-COMM+232.PCI employs a unique clocking option that allows the
end user to select from divide by 4, divide by 2 and divide by 1 clocking modes.
These modes ar e selected at Headers J1C through J4C.
To select the Baud rates commonly associated with COM: ports (i.e. 2400, 4800,
9600, 19.2, … 115.2K Bps ) place the jumper in the divide by 4 mode (silk-screen
DIV4) position.
DIV1
DIV2
DIV4
Figure 1 - Clocking Mode 'Divide By 4’
Omega Engineering COMM+232.PCI Page 2
Card Setup
To double these rates up to a maximum rate of 230.4K bps place the jumper in the
divide by 2 (silk-screen DIV2) position.
DIV1
DIV2
DIV4
Figure 2 - Clocking Mode 'Divide By 2’
Baud Rates and Divisors for the ‘DIV2’ mode
The following table shows some common data rates and the rates you should
choose if using the adapter in the ‘DIV2’ mode.
If your communications package allows the use of Baud rate divisors, choose the
appropriate divisor from the following table:
For this Data Rate Choose this Divisor
1200 bps 384
2400 bps 192
4800 bps 96
9600 bps 48
19.2K bps 24
38.4K bps 12
57.6K bps 8
115.2K bps 4
230.4K bps 2
460.8K bps 1
Omega Engineering COMM+232.PCI Page 5
Notes Page
Omega Engineering COMM+232.PCI Page 6
Installation
Installation
Operating System Installation
Windows 95/98/NT
Run Setup on Disk 2 of the Serial Utilities Software.
Windows 3.1x
Refer to the Win3x.hlp file in the \Win31 directory on Disk 1 of the Serial
Utilities Software.
DOS
Refer to the Readme.txt file found in the \DOS directory on Disk 1 of the
Serial Utilities Software.
Other Operating Systems
Refer to the appropriate directory on Disk 1 of the Serial Utilities Software.
Hardware Installation
The OMG-COMM+232.PCI can be installed in any of the PCI expansion slots
and contains several jumper straps for each port that must be set for proper
operation.
1. Turn off PC power. Disconnect the power cord.
2. Remove the PC case cover.
3. Locate an available PCI slot and remove the blank metal slot cover.
4. Gently insert the OMG-COMM+232.PCI 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.
Omega Engineering COMM+232.PCI Page 7
Technical Description
Technical Description
The Omega Engineering OMG-COMM+232.PCI provides a PCI interface adapter
with 2 asynchronous serial ports providing a versatile interface for modems,
printers and plotters.
The OMG-COMM+232.PCI utilizes the 16550 UART. This chip features
programmable baud rates, 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.
Interrupts
A good description of an interrupt and it’s importance to the PC can be found in
the book ‘Peter Norton’s Inside the PC, Premier Edition’:
“ One of the key things that makes a computer different from any other kind of
man-made machine is that computers have the capability to respond to the
unpredictable variety of work that comes to them. The key to this capability is a
feature known as interrupts. The interrupt feature enables the computer to
suspend whatever it is doing and switch to something else in response to an
interruption, such as the press of a key on the keyboard.”
A good analogy of a PC interrupt would be the phone ringing. The phone ‘bell’
is a request for us to stop what we are currently doing and take up another task
(speak to the person on the other end of the line). This is the same process the
PC uses to alert the CPU that a task must be preformed. The CPU upon receiving
an interrupt makes a record of what the processor was doing at the time and
stores this information on the ‘stack’; this allows the processor to resume its
predefined duties after the interrupt is handled, exactly where it left off. Every
main sub-system in the PC has it’s own interrupt, frequently called an IRQ (short
for Interrupt ReQuest).
In these early days of PC’s Omega Engineering decided that the abilit y to share
IRQs was an important feature for any add-in I/O card. Consider that in the IBM
XT the available IRQs were IRQ0 through IRQ7. Of these interrupts only IRQ2-5
and IRQ7 were actually available for use. This made the IRQ a very valuable
system resource. To make the maximum use of these system resources Omega
Engineering devised an IRQ sharing circuit that allowed more than one port to
use a selected IRQ. This worked fine as a hardware solution but presented the
software designer with a challenge to identify the source of the interrupt. The
software designer frequently used a technique referred to as ‘round robin
Omega Engineering COMM+232.PCI Page 8
Technical Description
polling’. This method required the interrupt service routine to ‘poll’ or interrogate
each UART as to its interrupt pending status. This method of polling was
sufficient for use with slower speed communications, but as modems increased
their throughput abilities this method of servicing shared IRQs became
inefficient.
Why use an ISP?
The answer to the polling inefficiency is the Interrupt Status Port (ISP). The ISP
is a read only 8-bit register that sets a corresponding bit when an interrupt is
pending. Port 1 interrupt line corresponds with Bit D0 of the status port, Port 2
with D1 etc. The use of this port means that the software designer now only has
to poll a single port to determine if an interrupt is pending.
The ISP is at Base+7 on each port (Example: Base = 280 Hex, Status Port = 287,
28F… etc.). The OMG-COMM+232.PCI will allow any one of the available
locations to be read to obtain the value in the status register. Both status ports
on the OMG-COMM+232.PCI are identical, so any one can be read.
Example: This indicates that Channel 2 has an interrupt pending.
Bit Position: 7 6 5 4 3 2 1 0
Value Read: 0 0 0 0 0 0 10
Connector Pin Assignments
RS-232
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
Note: These assignments meet EIA/TIA/ANSI-574 DTE for DB-9 type
connectors.
Omega Engineering COMM+232.PCI Page 9
Specifications
Specifications
Environmental Specifications
Specification Operating Storage
Temperature Range
Humidity Range 10 to 90% R.H.
Manufacturing
• All Omega Engineering 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.
A Serial Utility Diskette is supplied with the Omega Engineering adapter and will
be used in the troubleshooting procedures. By using this diskette 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 Omega Engineering 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 Omega Engineering adapter is using a unique IRQ. While the
Omega Engineering adapter does allow the sharing of IRQs, many other
adapters (i.e. SCSI adapters & on-board serial ports) do not. 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 Omega Engineering adapter is securely installed in a
motherboard slot.
5. When running DOS, Windows 3.x or other operating systems refer to the
Serial Utilities Disk 1 and the User Manual to verify that the Omega
Engineering 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 README.txt file on the supplied
diskette for detailed instructions on using 'SSD'.
6. For Windows 95/98 and Windows NT, the diagnostic tool 'WinSSD' is
installed in the Omega Engineering 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.
Always use the Omega Engineering diagnostic software when troubleshooting a
problem. This will help eliminate any software issues and identify any hardware
conflicts
Omega Engineering COMM+232.PCI Page 11
Appendix B - How To Get Assistance
Appendix B - How To Get Assistance
Please refer to Appendix A - Troubleshooting prior to calling Technical Suppor t.
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 installed in a computer ready to run diagnostics.
RETURN AUTHORIZATION MUST BE OBTAINED FROM OMEGA
ENGINEERING BEFORE RETURNED MERCHANDISE WILL BE ACCEPTED.
AUTHORIZATION CAN BE OBTAINED BY CALLING OMEGA
ENGINEERING AND REQUESTING A RETURN MERCHANDISE
AUTHORIZATION (RMA) NUMBER.
Omega Engineering COMM+232.PCI Page 12
Appendix C – Electrical Interface
Appen dix 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 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 OMG-COMM+232.PCI is a DTE device.
Omega Engineering COMM+232.PCI Page 13
Appendix D - Asynchronous Communications
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 transmittin g
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 boundarie s for asynchronous communications.
The end of the character is defined by the transmission of a pre -defined number
of stop bits (usual 1, 1.5 or 2). An extra bit used for error detection is often
appended before the stop bits.
Idle state of
line
1
0
5 to 8 Data Bits
Figure 4 - Asynchronous Communications Bit Diagram
Odd, Even
or
Unused
P
BIT
STOP
Remain Idle or
next start bit
1
1.5
2
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).
Omega Engineering COMM+232.PCI Page 14
Appendix E - Silk-Screen
Appendix E - Silk -Screen
5.0"
4.2"
Omega Engineering COMM+232.PCI Page 15
Warranty
Appendix F - 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 instructio n 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 A - “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 indust ry
• EN60950 (IEC950) - “Safety of information technology equipment, including electrical business equipment”
Warning
This is a Class A Product. In a domestic environment this product may cause
radio interference in which case the user may be required to take adequate
measures.
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.
Omega Engineering COMM+232.PCI Page 16
WARRANTY/DISCLAIMER
OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a
period of 13 months from date of purchase. OMEGA’s WARRANTY adds an additional one (1) month
grace period to the normal one (1) year product warranty to cover handling and shipping time. This
ensures that OMEGA’s customers receive maximum coverage on each product.
If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer Service
Department will issue an Authorized Return (AR) number immediately upon phone or written request.
Upon examination by OMEGA, if the unit is found to be defective, it will be repaired or replaced at no
charge. OMEGA’sWARRANTY does not apply to defects resulting from any action of the purchaser, including but not limited to mishandling, improper interfacing, operation outside of design limits,
improper repair, or unauthorized modification. This WARRANTY is VOID if the unit shows evidence of
having been tampered with or shows evidence of having been damaged as a result of excessive corrosion;
or current, heat, moisture or vibration; improper specification; misapplication; misuse or other operating
conditions outside of OMEGA’s control. Components which wear are not warranted, including but not
limited to contact points, fuses, and triacs.
OMEGA is pleased to offer suggestions on the use of its various products. However,
OMEGA neither assumes responsibility for any omissions or errors nor assumes liability for any
damages that result from the use of its products in accordance with information provided by
OMEGA, either verbal or written. OMEGA warrants only that the parts manufactured by it will be
as specified and free of defects. OMEGA MAKES NO OTHER WARRANTIES OR
REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESS OR IMPLIED, EXCEPT THAT OF TITLE,
AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. LIMITATION OF
LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total liability of
OMEGA with respect to this order, whether based on contract, warranty, negligence,
indemnification, strict liability or otherwise, shall not exceed the purchase price of the
component upon which liability is based. In no event shall OMEGA be liable for
consequential, incidental or special damages.
CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a “Basic
Component” under 10 CFR 21 (NRC), used in or with any nuclear installation or activity; or (2) in medical
applications or used on humans. Should any Product(s) be used in or with any nuclear installation or
activity, medical application, used on humans, or misused in any way, OMEGA assumes no responsibility
as set forth in our basic WARRANTY/DISCLAIMER language, and, additionally, purchaser will indemnify
OMEGA and hold OMEGA harmless from any liability or damage whatsoever arising out of the use of the
Product(s) in suc h a manner.
RETURN REQUESTS/INQUIRIES
Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department. BEFORE
RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST OBTAIN AN AUTHORIZED RETURN
(AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID
PROCESSING DELAYS). The assigned AR number should then be marked on the outside of the return
package and on any correspondence.
The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent
breakage in transit.
FOR W
ARRANTY
RETURNS, please have the
following information available BEFORE
contacting OMEGA:
1. Purc hase Order number under which the product
was PURCHASED,
2. Model and serial number of the product under
warranty, and
3. Repair instructions and/or specific problems
relative to the product.
FOR NON-W
ARRANTY
REPAIRS,
consult OMEGA
for current repair charges. Have the following
information available BEFORE contacting OMEGA:
1. Purchase Order number to cover the COST
of the repair,
2. Model and serial number of the product, and
3. Repair instructions and/or specific problems
relative to the product.
OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible. This affords
our customers the latest in technology and engineering.
reproduced, translated, or reduced to any electronic medium or machine-readable form, in whole or in part, without the
prior written consent of OMEGA ENGINEERING, INC.