SeaLevel SIO4-104.485 User manual

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
SIO4-104.485
User Manual | 3543

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
Contents
CONTENTS...........................................................................................................................................................2
INTRODUCTION ................................................................................................................................................... 3
BEFORE YOU GET STARTED ...............................................................................................................................4
CARD SETUP ........................................................................................................................................................6
SOFTWARE INSTALLATION ................................................................................................................................9
PHYSICAL INSTALLATION................................................................................................................................11
ELECTRICAL CHARACTERISTICS .....................................................................................................................14
APPENDIX A – TROUBLESHOOTING................................................................................................................15
APPENDIX B – HOW TO GET ASSISTANCE .....................................................................................................16
APPENDIX C – ELECTRICAL INTERFACE ........................................................................................................17
APPENDIX D – ASYNCHRONOUS COMMUNICATIONS ..................................................................................17
APPENDIX E – SILK SCREEN – 3542 PCB .......................................................................................................19
WARRANTY ........................................................................................................................................................20

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
Introduction
The SIO4-104.485, Item Number 3543, is a PC/104 module that provides four, RS-422/485 serial interface
ports. The board is designed using the XR16C554 UART, which provides a 16-byte FIFO.
In addition to the standard XR16C554 UART, the XR16C854 (‘SE’ option) and the OX16C954 (‘SN’ option)
are available. Both UARTS feature enhanced FIFOs (128 byte transmit and receive), and both maintain
compatibility with the XR16C554. The OX16C954 additionally features a flexible clock prescalar (from 1 to
31.875), 9-bit protocol, and an isochronous mode.
RS-422 provides excellent communications for long distance device connections up to 4000 ft., where
noise immunity and high data integrity are essential.
RS-485 is optimized for ‘Multi-Drop’ or ‘Party-line’ operations selecting data from multiple peripherals (as
many as 31 devices can be connected on an RS-485 bus).
The SIO4-104.485 is designed to be used with a variety of Operating Systems including Windows
98/NT/ME/2000/XP, Linux, and DOS. The SeaCOM API (Application Programmer Interface) available for
the SIO4-104.485 provides a variety of useful high-level function calls implemented as a Windows dynamic
link library (DLL) and as a Linux kernel module and library. In addition to the API, SeaCOM includes sample
code and utilities to simplify software development.
Other Sealevel PC104 Serial Interface Products
•ULTRA SIO-104 (Item Number 3550) - Single Port RS-422/485
•SIO-104 (Item Number 3551) - Single Port RS-232
•SIO.104+2 (Item Number 3502) - Dual Port RS-232/422/485
•C4-104.ULTRA (Item Number 3540) - Four Port RS-232/422/485
•SIO4-104.232 (Item Number 3542) - Four Port RS-232
•SIO4-104.2+2 (Item Number 3544) - Two Port RS-232 / Two Port 422/485

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
Before You Get Started
What’s Included
The SIO4-104.485 is shipped with the following items. If any of these items is missing or damaged, please
contact Sealevel for replacement.
•SIO4-104.485 Adapter
Advisory Conventions
Warning
The highest level of importance 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 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 used to provide background information, additional tips, or other
non-critical facts that will not affect the use of the product.

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
Optional Items
Depending upon your application, you are likely to find one or more of the following items useful with the
SIO4-104.485. All items can be purchased from our website (www.sealevel.com) or by calling our sales
team at 864-843-4343.
Cables Options
•IDC 40 to (4) DB9 Male connectors, 8” in length - (Item Number CA228)
Terminates the SIO4-104.485’s 40-pin header to four DB9M connectors.
•DB37 Male to 6” IDC40 Ribbon Cable and (1) DB37 to (4) DB9 Males, 36” in length - (Item
Number CA110/CA143)
This combination of cables also terminates the SIO4-104.232’s 40-pin header to four
DB9M connectors. The CA110 provides a bulkhead mountable DB37 Male connector and
the CA143 provides a DB37 to 4 DB9 male connectors via a 36-inch ‘Spider’ cable.
•IDC40 to 18” IDC40 Ribbon Cable and IDC40 to (4) DB9 Male Terminal Block - (Item Number
CA222/TB10)
This combination of cables also terminates the SIO4-104.485’s40-pin header to four
DB9M connectors via a bulkhead mountable terminal block assembly. It provides four DB9
male connectors that can easily be integrated into the Sealevel Systems Relio line of
embedded I/O servers.
•DB9 Male to DB9 Female Optomux adapter (Item Number DB103)
The DB103 is designed to convert a Sealevel DB9 Male connector to a pinout compatible
with AC24AT and AC422AT Opto-22 ISA bus cards. This allows Optomux devices to be
controlled from any Sealevel RS-422 board with a DB9 Male connector.
•DB9 Male to DB9 Male Sony 207M adapter cable (Item Number CA190)
This cable allows any Sealevel RS-422 adapter with a DB-9 to connect directly to a Sony (or
compatible) 207M "9 Pin" connector.

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
Card Setup
Address Selection
The SIO4-104.485 occupies 16 consecutive I/O locations. The DIP-switch (SW1) is used to set the base
address for these locations and the IRQ mode options. Be careful when selecting the base address as some
selections conflict with existing PC ports. The following table shows the addressing options available. If
different address options are required, please contact Sealevel Systems Technical Support about a custom
PAL option.
SW1-1
SW1-2
SW1-3
Port 1
Port 2
Port 3
Port 4
Off
Off
On
300
310
320
330
Off
On
Off
400
410
420
430
Off
On
On
500
510
520
530
On
Off
Off
600
610
620
630
On
Off
On
1500
1510
1520
1530
On
On
Off
3220
3230
3240
3250
On
On
On
4220
4230
4240
4250
Interrupt Modes
DIP-Switch positions ‘S’ and ‘M’ on switch SW1 selects the interrupt mode for each adapter.
With the ‘S’ selected, the adapter is in a (S)hared interrupt mode, which allows more than one adapter to
access a single IRQ.
‘M’ indicates the inclusion of a 1K-ohm pull-down resistor required on one adapter when sharing interrupts.
Set the switch to ‘S’ for shared interrupt mode on all adapters sharing an IRQ. On one of the adapters sharing
an interrupt set the switches for both ‘S’ and for ‘M’. This provides the pull-down resistor circuit that makes
sharing IRQs possible. If you are using more than one compatible adapter in a bus, you should only have
one adapter set to ‘M’.
IRQ Selection
The SIO4-104.485 has an interrupt selection jumper, which should be set prior to use, if an interrupt is
required by your application software. Consult the user manual for the application software being used to
determine the proper setting.

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
Clock Modes
The SIO4-104.485 utilizes a 14.7456 MHz oscillator. This is eight times faster than the standard COM: port
oscillator, which typically is 1.8432 MHz. This allows the adapter to achieve a maximum data rate of
921.6Kbps. The following sections outline the baud rate calculations and instructions for achieving your
desired baud rate.
Baud Rates and Oscillator value
The following table shows some common data rates and the rates you should choose to achieve them
when using the SIO4-104.485 . If the O/S of choice is Windows 95/98/ME/2000/NT/XP, the oscillator value
(14.7456 MHz) should be entered into the ‘Advanced Tab’ on 95/98/Me/2000/XP Device Manager applet.
Typically this is done automatically when the Sealevel Software driver is loaded.
When using Windows NT, the ‘Advanced Ports’ applet in the Control Panel should be launched and the
oscillator value entered manually in the ‘Advanced’ tab, or all data rates will be eight (8) times the selected
rate. For example if a data rate of 19.2Kbps is selected, the actual data rate will be 153.6Kbps.
When using any other OS (i.e. Linux, or QNX) the following table should be used.
For this Data Rate
Choose this Data Rate
1200 bps
150 bps
2400 bps
300 bps
4800 bps
600 bps
9600 bps
1200 bps
19.2K bps
2400 bps
57.6 K bps
4800 bps
115.2 K bps
14.4K bps
230.4K bps
28.8K bps
460.8K bps
57.6 K bps
921.6K bps
115.2 K bps

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
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
768
2400 bps
384
4800 bps
192
9600 bps
96
19.2K bps
48
38.4K bps
24
57.6K bps
12
115.2K bps
8
230.4K bps
4
460.8K bps
2
921.6K bps
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Electrical Interface Selection
Each of the ports on the SIO4-104.485 can be individually configured as RS-422, or as a two wire RS-485
interface. This is a software selectable feature and is found at Base+15. To enable a port for RS-422, simply
write a ‘0’ to Base+15 (this is the power up default). To enable a port for two-wire RS-485 simple write a ‘1’
to Base+15. If the Sealevel Software Windows drivers are used, this is accomplished as a function of the
Device Manager.
RS-485 Enable
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 PCs to be connected in a multi-drop bus and selectively polled. Half-duplex
two-wire operation is also possible by connecting TX+ to RX+ and TX- to RX- in your cable hood. The enable
to the driver is connected to the UART Request to Send (RTS) line for RS-485 communications. This allows
the RS-485 driver to be tri-stated when inactive on a multi-drop polled network. The software that you are
using must "know how" to enable the driver when it is answering a poll. Failure to correctly utilize the enable
can cause transmitter contention problems preventing operation by any node on the network. If the Sealevel
Systems Windows Software driver is used, a ‘Radio’ style button on the ‘Advanced’ property page under the
Device manager can be selected that will automatically toggle RTS for use as an enable.

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
If the SIO4-104.485 is equipped with the optional 16C954, (Item Number 3543-SN) a hardware mode can
be selected in the UART that will also enable the RS-485 drive automatically.
Line Termination
Typically, each end of the RS-485 bus must have line-terminating resistors (RS-422 terminates at the receive
end only). Typically a 120-ohm resistor is across each RS-422/485 input in addition to a 1K-ohm pull-
up/pull-down combination that biases the receiver inputs. If multiple SIO4-104.485 adapters are configured
in an RS-485 network, only the boards on each end should have the termination in place. Contact Sealevel
Technical Support if you have questions on how to remove this termination.
RS-485 ‘Echo’
The RS-485 ‘Echo’ is the result of connecting the receiver inputs to the transmitter outputs. Every time a
character is transmitted; it is also received. The SIO4-104.485 automatically suppresses this ‘Echo’.
Software 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
[email protected] to receive access to the proper driver download and installation
instructions.
1. Begin by locating, selecting, and installing the correct software from the website -
SeaCOM software.
2. Select the “SeaCOM for Windows” download link.
3. The setup file will automatically detect the operating environment and install the
proper components.
To confirm that the SeaCOM driver has been successfully installed, click on the ‘Start’ button, and then
select ‘All Programs’. You should see the ‘SeaCOM’ program folder listed.
You are now ready to proceed with connecting the 3543 to your system. Refer to the Hardware
Installation section for details.

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© Sealevel Systems, Inc. 3543 Manual | SL9119 9/2022
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
seacom/utilities/3543mode.
3rd Party Software Support
Third party software support for many HMI/MMI and other process control software is accessible through
links on the Sealevel’s website. For the most up to date information on third party software support, please
visit: https://www.sealevel.com/support/3rd-party-software-support/.
For additional software support, including QNX, please call Sealevel Systems’ Technical Support, (864) 843-
4343. Our technical support is free and available from 8:00 AM - 5:00 PM Eastern Time, Monday through
Friday. For email support contact: [e-mail].