ICS Advent PCI-ICOM485/4 User manual

Model PCI-ICOM485/4
PCI-ICOM485/2
Product Manual
MANUAL NUMBER : 00650-148-1C

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FOREWORD
This product manual provides information to install, operate and or program the referenced product(s)
manufactured or distributed by ICS Advent. The following pages contain information regarding the
warranty and repair policies.
Check our Web site (www.icsadvent.com) for technical information, manuals, and BIOS updates.
Technical assistance is also available at: 800-480-0044 (U.S.) or 858-677-0877 (international).
Customer Comments: If you experience any problems with this manual or just want to provide some
feedback, please send us a message using the online "Service Form" on our Web site (www.icsadvent.com)
under "Support." Detail any errors you find. We will correct the errors or problems as soon as possible and
post the revised manual in our online Support Library. Thank you.
The information in this document is provided for reference only. ICSAdvent does not assume any liability
arising from the application or use of the information or products described herein. This document may
contain or reference information and products protected by copyrights or patents and does not convey any
license under the patent rights of ICS Advent, nor the rights of others.
Copyright © 1998, a California Corporation, 6260 Sequence Drive, San Diego, CA92121-4371. ICSAdvent
is a Registered Trademark of ICS Advent. All trademarks and registered trademarks are the property of
their respective owners. All rights reserved. Printed in the United States of America. No part of this publi-
cation may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, elec-
tronic, mechanical, photocopying, recording , or otherwise, without the prior written permission of the pub-
lisher.

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Shipments not in compliance with this Guarantee
and Limited Warranty Return Policy will not be ac-
cepted by ICS Advent.
Guarantee
A thirty day money-back guarantee is provided on all standard products sold. Special order products are
covered by our Limited Warranty, however they may not be returned for refund or credit. EPROMs,
RAM, Flash EPROMs or other forms of solid electronic media are not returnable for credit - but for
replacement only. Extended Warranty available. Consult factory.
Refunds
In order to receive a refund on a product for the purchase price, the product must not have been
damaged by the customer or by the common carrier chosen by the customer to return the goods and
the product must be returned complete (meaning all manuals, software, cables, etc.) within 30 days of
receipt and in an as-new and resalable condition. The Return Proceduremust be followed to assure
prompt refund.
Restocking Charges
Product returned after 30 days, and before 60 days, of the purchase will be subject to a minimum20%
restocking charge and charges for any damaged or missing parts. Products not returned within 60
days of purchase, or products which are not in an as-new and re-saleable condition, are not eligible
for credit return and will be returned to the customer.
Limited Warranty
Effective April 1, 1998, all products carry a 2-year limited warranty. Within two years of purchase,
ICS Advent will repair or replace, at our option, any defective product. ICS Advent will service the
warranty for all standard catalog products for the first two years from the date of shipment.
Please note: The 2-year warranty may not apply to special promotion items. Please consult the factory for
warranty verification.
The limited warranty is void if the product has been subjected to alteration, neglect, misuse, or abuse; if any
repairs have been attempted by anyone other than ICS Advent or its authorized agent; or if the failure is
caused by accident, acts of God, or other causes beyond the control of ICS Advent or the manufacturer.
Neglect, misuse, and abuse shall include any installation, operation, or maintenance of the product other than
in accordance with the user’s manual.
No agent, dealer, distributor, service company, or other party is authorized to change, modify, or extend the
terms of this Limited Warranty in any manner whatsoever. ICS Advent reserves the right to make changes
or improvements in any product without incurring any obligation to similarly alter products previously
purchased.

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Return Procedure
For any Guarantee or Limited Warranty return, please contact ICS Advent's Customer Service at
800-480-0044 (U.S.) or 858-677-0877 (international) and obtain a Return Material Authorization (RMA)
Number. All product(s) returned to ICS Advent for service or credit must be accompanied by a Return
MaterialAuthorization (RMA) Number. Freight on all returned itemsmust be prepaid by the customer who
is responsible for any loss or damage caused by common carrier in transit. Returns for Warranty must
include a Failure Report for each unit, by serial number(s), as well as a copy of the original invoice showing
date of purchase.
To reduce risk of damage, returns of product must be in an ICS Advent shipping container. If the original
container has been lost or damaged, new shipping containers may be obtained from ICS Advent Customer
Service at a nominal cost.
ICS Advent owns all parts removed from repaired products. ICS Advent uses new and reconditioned parts
made by various manufacturers in performing warranty repairs and building replacement products.
If ICS Advent repairs or replaces a product, its warranty term is not extended.
ICSAdvent will normally return your replacement or repaired items via Second DayAir. Overnight delivery
or delivery via other carriers is available at an additional charge.
Limitation of Liability
In no event shall ICS Advent be liable for any defect in hardware, software, loss, or inadequacy of data of
any kind, or for any direct, indirect, incidental, or consequential damages in connection with or arising out of
the performance or use of any product furnished hereunder. ICSAdvent liability shall in no event exceed the
purchase price of the product purchased hereunder. The foregoing limitation of liability shall be equally
applicable to any service provided by ICSAdvent or its authorized agent.
Some Sales Items and Customized Systems are not subject to the guarantee and limited warranty.
However in these instances , any deviations will be disclosed prior to sales and noted in the original invoice.
ICS Advent reserves the right to refuse returns or credits on software or special order items.

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Advisories
Three types of advisories are used throughout the manual to stress important points or warn of potential
hazards to the user or the system. They are the Note, the Caution, and theWarning. Following is an example
of each type of advisory:
Note: The note is used to present special instruction, or to provide extra information which may
help to simplify the use of the product.
CAUTION!
A Caution is used to alert you to a situation which if ignored may cause injury or
damage equipment.
WARNING!
AWarningisusedtoalertyouofasituationwhichifignoredwillcauseseriousinjury.
Cautions and Warnings are accented with triangular symbols. The exclamation symbol is used in all cautions
and warnings to help alert you to the important instructions. The lightning flash symbol is used on the left
hand side of a caution or a warning if the advisory relates to the presence of voltage which may be of
sufficient magnitude to cause electrical shock.
Use caution when servicing any electrical component. We have tried to identify the areas which may pose
a Caution or Warning condition in this manual; however, ICS Advent does not claim to have covered all
situations which might require the use of a Caution or Warning.
You must refer to the documentation for any component you install into a computer system to ensure proper
precautions and procedures are followed.

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Table of Contents
Chapter 1: Installation ..................................................................................................1
Backing Up the Disk............................................................................................................................. 1
HardDiskInstallation............................................................................................................................ 1
InstallingtheCard ................................................................................................................................. 3
Input/OutputConnections ..................................................................................................................... 5
Chapter 2: Functional Description..............................................................................7
RS-485BalancedModeOperation ........................................................................................................ 7
Comm Port Compatibility ...................................................................................................................... 7
CommunicationMode ........................................................................................................................... 7
BaudRateRanges................................................................................................................................8
Auto-RTSTransceiverControl ............................................................................................................... 8
Block Diagram ...................................................................................................................................... 8
Chapter 3: Option Selection ........................................................................................9
Terminations ......................................................................................................................................... 9
DataCableWiring................................................................................................................................. 9
BaudRateRanges...............................................................................................................................10
Interrupts .............................................................................................................................................10
Chapter 4: Address Selection.................................................................................... 13
Chapter 5: Programming ...........................................................................................15
Sample Programs ................................................................................................................................15
RS-422and RS-485 Programming .......................................................................................................15
Initialization .........................................................................................................................................15
BaudRateDivisorValues.....................................................................................................................16
Reception ............................................................................................................................................17
Transmission .......................................................................................................................................18
Chapter 6: Connector Pin Assignments...................................................................19
Chapter 7: Specification ............................................................................................21
Current Revision 1C
December 2000

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Chapter 1: Installation
Backing Up the Disk
Thesoftwaresupplied withthePCI-ICOM485/4(/2)is providedontwo3.5-inchdiskettes. As with
any software package, you should make backup copies for everyday use and place your original
master diskettes in a safe location.
The easiest way to make a backup copy is to use the DOS DISKCOPY utility.
In a single-drive system, the command is diskcopy a: a: Enter
Ina windowed environment(suchasOS2,Windows3.1,Windows95,orWindowsNT) selectallof
the files on the diskette and drag them to a backup destination.
Hard Disk Installation
The files contained on the master diskette must be installed onto your hard disk prior to use. To do
this, perform the following:
1. Place the master diskette into the A: drive (substitute B: as appropriate).
2. Change the active drive to A: by typing a:Enter
3. Type install Enter and follow the on-screen prompts.
The installation process will create several directories on your hard disk. If you accept the instal-
lation defaults, the following structure will exist.
Contents of the PCI-ICM4S dISKETTE
Bold indicates directory name.
PCI-ICM4S Root or base directory containing the SETUP.EXE setup program used to
help you configure jumpers and options on the card. The directory also
contains PCIFind.EXE, a utility to locate resources used by installed PCI-
bus cards.
PSAMPLES A subdirectory of PCI-ICM4S that contains Pascal samples.
CSAMPLES A subdirectory of PCI-ICM4S that contains “C” samples.
BSAMPLES A subdirectory of PCI-ICM4S that contains QuickBASIC samples.
Contents of the Tools/Utilities Diskette
Bold indicates directory name.
VBACCES Sixteen-bit DLL drivers for use with VisualBASIC 3.0 and Windows 3.1
only. Thesedriversprovidefourfunctions,similartotheACCES32DLL.
However,this DLLisonlycompatible with16-bitexecutables. Migration
from 16-bit to 32-bit is simplified because of the similarity between
VBACCES and ACCES32.

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PCI-ICOM485/4Manual
ACCES95 and
ACCESNT Thesetwodriversarementionedforusersmigratingfromolderversionsof
ACCES Tools. The functionality of ACCES95 and ACCESNT has been
combinedintoACCES32.DLL,whichisdescribedbelow.
InordertomodifyyoursoftwaretousethenewACCES32.DLLinsteadof
theoldercode,changethefileyoulinktofromACCES95orACCESNTto
ACCES32. No other changes are necessary.
ToavoidrecompilingsoftwarethatwaswrittenforACCES95orACCESNT,
rename ACCES32.DLL to the appropriate name (95 or NT specific).
ACCES32 This directory contains the Windows 95/98/NT driver used to provide
access to the hardware registers when writing 32-bit Windows software.
Severalsamplesareprovidedinavarietyoflanguagestodemonstratehow
to use this driver. The DLL provides four functions (InPortB, OutPortB,
InPort, and OutPort) to access the hardware.
This directory also contains the device driver and install program for NT.
This device driver provides register-level hardware access from Windows
NT, normally called through ACCES32.DLL. Two methods of using the
driver are provided, the ACCES32.DLL (recommended) and the
DeviceIOControl handles direct to the SYS file (slightly faster)
ACCESNT.EXE RunthisprogramonWindowsNTtoprepareACCES32.DLLforuse. This
istheinstallprogramfortheSYSfileitself. TheACCESNT.SYSfilemust
reside in the same directory as this executable, and is copied to the drivers
directory of NT. The driver is then dynamically started, and can be used
immediately. ACCESNT.EXEneedberunonlyoncepercomputer. Once
the driver is started, the registry entries tell WindowsNT to load the driver
on each boot-up.
No installation is necessary for Windows 95/98.
DLL SamplesforusingACCES32.DLLareprovidedinthisdirectory. Usingthis
DLLnotonlymakesthehardwareprogrammingeasier(MUCHeasier),but
alsoonesourcefilecanbeusedforbothWindows95/98andWindowsNT.
One executable can run under both operating systems and still have full
access to the hardware registers. The DLL is used exactly like any other
DLL, so it is compatible with any language capable of using 32-bit DLLs.
Consultthemanualsprovidedwithyourlanguage’scompilerforinformation
on using DLLs in your specific environment.
SYS The samples in this directory are provided ONLY for WindowsNT. The
DeviceIOControl based interaction with the register-level driver is only
availablein NT. Ifyourcode iswrittento usethismethod,it willnotwork
with Windows 95 or Windows 98.
TheSYSfileistheactualworkhorsebehindhardwareaccessinWindowsNT.
It is installed by ACCESNT.EXE and utilizes the DeviceIOControl API
functionforinteractionwithusercode. Samplesareprovideddemonstrating
thisAPIcall,butitisstronglyrecommendedthattheDLLinterfacebeused.
The DLL described above encapsulates the SYS file and performs the
DeviceIOControlcallsata small penalty in speed (a call through the DLL
interface).

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INSTALL.SRC Source code for ACCESNT.EXE is provided herein to allow you to write
OEMversionsoftheprogramortointegrateitsfunctionalityintoyourown
code.
PCI This directory contains PCI-bus specific programs and information.
PCIFind A utility for DOS and 16-bit Windows to determine PCI bus resources
allocated to installed PCI cards. Use this utility to find what base address
andIRQyourcardsareinstalledatonthePCIbus. UsethefilesinthePCI32
directory when running in Windows95/98/NT to perform the same task.
BIOS A utility program is provided with source code you can use to determine
allocated resources at run-time from your own programs.
PCI32 ThisprogramisusedtodeterminethebaseaddressandIRQofinstalledPCI
cards in Windows 95/98 and NT. Run this program to both install and use
NTioPCI.SYS or PCIFind.DLL. This program modifies the registry by
adding a registry key describing the hardware that was detected. For
information about the format of the registry key, consult the card-specific
samplesprovidedwiththehardware. InWindowsNT,NTioPCI.SYSruns
each time the computer is booted, thereby refreshing the registry as PCI
hardwareisaddedorremoved. InWindows95/98,PCI32.EXEplacesitself
in the boot-sequence of the OS to refresh the registry on each power-up.
This program used to be known as PCINT.EXE, but now supports both
Windows 95/98 and Windows NT.
Findbase.exe DOS utility to determine an available base address for ISA bus , non-PNP
cards. Run this program once, before the hardware is installed in the
computer, to determine an available address to give the card. Once the
address has been determined, run the setup program provided with the
hardware to see instructions on setting the address switch and various
option selections.
Poly.exe A generic utility to convert a table of data into an nth order polynomial.
Useful for calculating linearization polynomial coefficients for
thermocouples and other non-linear sensors.
Risc.bat AbatchfiledemonstratingthecommandlineparametersofRISCTerm.exe.
RISCTerm.exe A dumb-terminal type communication program designed for RS422/485
operation. Used primarily with REMOTE ACCES data acquisition Pods
andourRS422/485serialcommunicationproductline. Canbeusedtosay
hello to an installed modem. RISCTerm stands for Really Incredibly
Simple Communications TERMinal.
Installing the Card
The PCI-ICOM485/4 (/2) card can be installed in a five-Volt PCI slot of an IBM or compatible
computer. Before installing the card, carefully read the Option Selection section of this manual
andconfigurethecardaccordingtoyourrequirements.Finally, our SETUP.EXE program will lead
youthroughthe process of setting the options onthePCI-ICOM485/4(/2)card.The setup program
does not set the options. These must be set manually by jumpers on the card.

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Toinstallthe card:
1. Turn OFF computer power.
2. Remove the computer cover.
3. Install jumpers from either the Option Selection section of this manual or the suggestions
of our SETUP.EXE software program.
4. Install the card in an available PCI-bus slot.
5. Inspect for proper fit of the card and tighten screws. Make sure that the card mounting
bracket is properly screwed into place and that there is a positive chassis ground.
6. Replace the computer cover and turn the computer ON.
7. EntertheCMOSsetupprogramofyoursystemandverifythatthePCIplug-and-playoption
is set appropriately for your system. Systems running Windows95 (or any other PNP-
compliant Operating System) should set the CMOS option to OS. Systems running under
DOS,WindowsNT3.51,Windows3.1,oranyothernon-PNP-compliantOperatingSystem
should set the PNP CMOS option to BIOS or Motherboard. Save the option and continue
booting the system.
If you are using Windows95, your operating system should detect the new hardware and prompt
you for the installation disk. Insert the provided diskette into the A drive and allow the operating
system to look for the files that it wants.
The base address assigned by BIOS or the operating system can change each time new hardware is
installed into or removed from the computer. Please re-check PCIFind or Device Manager if the
hardware configuration is changed,
PCI cards are assigned resources by the system. To determine the resource assigned, run PCIFind
(DOS/Win 3.1), PCINT(Win95/98/NT), or look in the operating systems list of Detected Devices.
In Win95/98/NT, this is the Device Manager of the system applet, found in the control panel. See
the Tools diskette for more information on PCIFind and PCINT.

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Input/Output Connections
The PCI-ICOM485/4 (/2) uses a 37-pin DBM connector. To connect to the serial device/s there
will be the DB37 connector on the card and a “spider” cable providing two or four DB9 female
connectors.
ToensurethatthereisminimumsusceptibilitytoEMIandminimumradiation,itisimportantthatthe
card mounting bracket be properly screwed into place and that there be a positive chassis ground.
Also, proper EMI cabling techniques (cable connect to chassis ground at the aperture, shielded
twisted-pairwiring,etc.) be used for the input/output wiring.
Data Cable Wiring- 37 Pin Connector
Signal Connector Pin Signal Connector Pin
COMA Tx+/Rx+ 37 COMC Tx+/Rx+ 27
COMA Tx-/Rx- 19 COMC Tx-/Rx- 9
COMA Gnd 18 COM C Gnd 8
COMBTx+/Rx+ 32 COMD Tx+/R+ 21
COMB Tx-/Rx- 14 COMD Tx-/Rx- 3
COMB Gnd 13 COMD Gnd 2
PIN Connections
COM Port A-D RS-485 Signals
Pin 1
Pin 2 Tx and Rx+
Pin 3 Tx and Rx+
Pin 4
Pin 5 GND Ground
Pin 6
Pin 7
Pin 8
Pin 9

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Chapter 2: Functional Description
The PCI-ICOM485/4 (/2) Serial Interface Card was designed for effective multipoint transmission
onlongcommunicationlinesinnoisyenvironmentsusingRS-485differentiallinedriversandRS-485
(EIA485) protocol. The data lines are opto-isolated from the computer and from each other to
assure communication when large common mode noise are superimposed. The card is 12.283
inches long and may be installed in 5-Volt PCI-bus slots of IBM PC or compatible computers. The
card features two or four (or two) independent, asynchronous RS-485 serial ports, type 16550
bufferedUARTS,and,forWindowscompatibility,automaticcontroltotransparentlyenable/disable
the transmission drivers. The output stages are optically coupled to provide electrical isolation be-
tween the computer and the I/O.
RS-485 Balanced Mode Operation
The PCI-ICOM485/4 (/2) supports RS-485 communications and uses differential balanced drivers
for long range and noise immunity. RS-485 operation involves switchable transceivers and the
ability to support multiple devices on a single “party line”. The RS-485 specification defines a
maximum of 32 devices on a single line. The number of devices served on a single line can be
expanded by use of “repeaters”.
The PCI-ICOM485/4 (/2) also has the capability to add load resistors to terminate the communica-
tions lines. RS-485 communications require that one transmitter supply a bias voltage to ensure a
known “zero” state when all transmitters are off. Also, receiver inputs at each end of the network
should be terminated to eliminate “ringing”. The PCI-ICOM485/4 (/2) supports biasing by default
and supports termination by jumpers on the card. If your application requires the transmitter to be
un-biased, please contact the factory.
Comm Port Compatibility
Type 16550 UART’s are used as the Asynchronous Communication Element (ACE). These in-
clude a 16-byte transmit/receive buffer to protect against lost data in multitasking operating sys-
tems, while maintaining 100% compatibility with the original IBM serial port. The system assigns
the address(es).
Acrystal oscillator is located on thecard. Thisoscillator permits precise selection of baudratesup
to 115,200 or, by changing a jumper, up to 460,800 with the standard crystal oscillator.
The driver/receiver used, the SN75176B, is capable of driving extremely long communication
lines at high baud rates. It can drive up to ±60 mA on balanced lines and receive inputs as low as
200 mV differential signal superimposed on common mode noise of +12 V or -7 V. In case of
communication conflict, the driver/receivers feature thermal shutdown.
Communication Mode
ThePCI-ICOM485/4(/2)supportshalf-duplexcommunicationswithatwo-wire cable connection.
Half-duplexallows traffic to travel in bothdirections,but only one way at atime. RS-485commu-
nications commonly use the half-duplex mode since they share only a single pair of wires.

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Baud Rate Ranges
The card has capability for two baud rate ranges and you can select which you wish to use on a
port-by-port basis. One range is for up to 115,200 baud applications and the other is up to 460,800
baud applications.
Note: Refer to Baud Rate Divisor Values on page 16 of the manual.
Auto-RTS Transceiver Control
In RS-485 communications, the driver must be enabled and disabled as needed, allowing all cards
to share a two wire cable. The PCI-ICOM485/4 (/2) card controls the driver automatically. With
automatic control, the driver is enabled when data is ready to be transmitted. The driver remains
enabled for one additional character’s transmission time after data transfer is complete and then is
disabled. The receiver is also normally enabled, then disabled during RS-485 transmissions, and
then re-enabled after transmission is completed (plus one character transmission time). The PCI-
ICOM485/4(/2)automaticallyadjustsitstimingtothebaudrateofthedata. (NOTE:Thankstothe
automatic control feature, the card is ideal for use in WIN95 applications.)
PCI-ICOM485/4 (/2) BLOCK DIAGRAM

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Chapter 3: Option Selection
To help you locate the jumpers described in this section, refer to the Option Selection Map at the
endofthis section. Operation of the serialcommunicationssectionis determined by jumper instal-
lation as described in the following paragraphs.
Terminations
Atransmissionlineshouldbeterminatedatthereceivingendinitscharacteristicimpedance.Installing
a jumper at the locations labeled LDxO applies a 120W load across the transmit/receive input/
output for RS-485 operation.
Simplified Termination Schematic
In RS-485 operations where there are multiple terminals, only the RS-485 ports at each end of the
network should have terminating impedance as described above. To so terminate the COMAport,
place a jumper at the location labeled LDAO. To terminate the COM B, COM C, and COM D
ports, place jumpers at locations labeled LDBO, LDCO, and LDDO respectively.
Also, for RS-485 operation, there must be a bias on the RX+ and RX- lines. If the PCI-ICOM485/
4 (/2) card is not to provide that bias, contact the factory technical support.
Data Cable Wiring- 37 Pin Connector
Signal Connector Pin Signal Connector Pin
COMA Tx+/Rx+ 37 COMC Tx+/Rx+ 27
COMA Tx-/Rx- 19 COMC Tx-/Rx- 9
COMA Gnd 18 COM C Gnd 8
COMB Tx+/Rx+ 32 COMD Tx+/R/X+ 21
COMB Tx-/Rx- 14 COMD Tx-/Rx- 3
COMB Gnd 13 COMD Gnd 2

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PCI-ICOM485/4Manual
Baud Rate Ranges
The jumpers labeled CLK X1 and CLK X4 provide means to select baud rates in either of two
ranges. When in the “X1” position, the baud rate range is up to 115,200 baud. When in the CLK
X4 position, the baud rate range is 200 to 460,800 baud.
Note: Refer to the Baud Rate DivisorValues on page 16 of the manual.
Interrupts
Please note that, in Windows NT, changes must be made to the system registry to support IRQ
sharing. The following is excerpted from “Controlling Multiport Serial I/O Cards” provided by
Microsoft in the MSDN library, documentid:mk:@ivt:nt40res/D15/S55FC.HTM, also available in
the WindowsNT Resource Kit. The Microsoft serial driver can be used to control many dumb
multiport serial cards. Dumb indicates that the control includes no onboard processor. Each port
ofamultiportcardhasaseparatesubkeyundertheHKLM\CurrentControlSet\Services\Serialsubkey
in the registry. In each of these subkeys, you must add values for DosDevices, Interrupt,
InterruptStatus, PortAddress, and PortIndex because these are not detected by the Hardware
Recognizer. (For descriptions and ranges for these values, see Regentry.hlp, the Registry help file
on the WindowsNT Workstation Resource Kit CD.)
For example, if you have a four-port PCI-ICOM485/4 (/2) card configured to use address 0xFC00,
0xFD00, 0xFD80, and 0xFE00 with an interrupt of 05, the values in the Registry are:
Serial2 subkey: Serial4 subkey:
PortAddress = REG_DWORD 0xFC00 PortAddress = REG_DWORD 0xFD80
Interrupt = REG_WORD 5 Interrupt = REG_DWORD 5
DosDevices = REG_SZ COM3 DosDevices = REG_SZ COM5
InterruptStatus = REG_DWORD 0xFC08 InterruptStatus = REG_DWORD 0xFC08
PortIndex = REG_DWORD 1 PortIndex - REG_DWORD 3
Serial3 subkey: Serial5 subkey:
PortAddress = REG_DWORD 0xFD00 PortAddress = REG_DWORD 0xFE00
Interrupt = REG_DWORD 5 Interrupt = REG_DWORD 5
DosDevices = REG_SZ COM4 Dos Devices = REG_SZ COM6
InterruptStatus = REG_DWORD 0xFCO8 InterruptStatus = REG_DWORD 0xFC08
PortIndex = REG_DWORD 2 PortIndex = REG_DWORD 4
As this example shows, the Interrupt status register, which indicates which port (s) caused an IRQ,
is located at COM A Base Address +8.

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PCI-ICOM485/4 (/2) OPTION SELECTION MAP

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