SeaLevel COMM+2 User manual

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
COMM+2
User Manual | 3083

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
Contents
CONTENTS...........................................................................................................................................................2
INTRODUCTION ................................................................................................................................................... 3
BEFORE YOU GET STARTED ...............................................................................................................................4
CARD SETUP ........................................................................................................................................................5
INSTALLATION .................................................................................................................................................... 9
TECHNICAL DESCRIPTION ...............................................................................................................................11
SPECIFICATIONS ...............................................................................................................................................13
APPENDIX A – TROUBLESHOOTING................................................................................................................14
APPENDIX B – HOW TO GET ASSISTANCE .....................................................................................................15
APPENDIX C – ELECTRICAL INTERFACE ........................................................................................................16
APPENDIX D - ASYNCHRONOUS COMMUNICATIONS....................................................................................18
APPENDIX E – SILK SCREEN ............................................................................................................................19
APPENDIX F – SCHEMATIC..............................................................................................................................20
APPENDIX G – COMPLIANCE NOTICES ..........................................................................................................21
WARRANTY ........................................................................................................................................................22

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
Introduction
Overview
The COMM+2 provides the PC with two async serial ports, which can interface, to RS-232, RS-422, or RS-
485.
Factory Default Settings
The COMM+2 factory default settings are as follows:
Port #
Base Address
IRQ
Electrical Specification
Port 1
3F8
4
RS-422
Port 2
2F8
3
RS-422
To install the COMM+2 using factory default settings, refer to Installation on page 6.
For your reference, record installed COMM+2 settings below:
Port #
Base Address
IRQ
Electrical Specification

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
Before You Get Started
What’s Included
The COMM+2 is shipped with the following items. If any of these items are missing or damaged, contact
the supplier.
•COMM+2 Serial I/O 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. 3083 Manual | SL9107 1/2023
Card Setup
The COMM+2 contains several jumper straps, which must be set for proper operation.
Address Selection
Each port on the COMM+2 occupies 8 consecutive I/O locations. A DIP-switch is used to set the base
address for these locations. Be careful when selecting the base address as some selections conflict with
existing ports. The following table shows several examples that typically do not cause a conflict. SW1 sets
the I/O address for port 1 of the COMM+2 and SW2 sets the address for port 2.
Address
Binary
Switch Position Setting
Hex
A9 A0
1
2
3
4
5
6
7
280-287
1010000XXX
Off
On
Off
On
On
On
On
2A0-2A7
1010100XXX
Off
On
Off
On
Off
On
On
2E8-2EF
1011101XXX
Off
On
Off
Off
Off
On
Off
2F8-2FF
1011111XXX
Off
On
Off
Off
Off
Off
Off
3E8-3EF
1111101XXX
Off
Off
Off
Off
Off
On
Off
300-307
1100000XXX
Off
Off
On
On
On
On
On
328-32F
1100101XXX
Off
Off
On
On
Off
On
Off
3F8-3FF
1111111XXX
Off
Off
Off
Off
Off
Off
Off
Figure 1 - Address Selection Table
The following illustration shows the correlation between the DIP-switch setting and the address bits used
to determine the base address. In the example below, address 300 Hex is selected as a base. Address 300
in binary is XX11 0000 0XXX where X = a non-selectable address bit.
Figure 2 - DIP-Switch Illustration
ON
1
3
8
7
6
5
4
2
EN
A3
A9

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
Setting the switch “On” or “Closed” corresponds to a “0” in the address, while leaving it “Off” or
“Open” corresponds to a “1”.
Refer to Appendix A for common address contentions.
Port Enable / Disable
Each port on the COMM+2 can be enabled or disabled with switch position 8 on the DIP-switch. The port is
enabled with the switch “On” or “Closed” and disabled when “Off” or “Open”. If any port is disabled, be sure
to disable the interrupt request for that port by removing the IRQ jumper.
IRQ Selection
Header E6 selects the interrupt request for each serial port. If COM1: is selected, the corresponding jumper
must be on the IRQ4 setting. If COM2: is selected, the corresponding jumper must be on IRQ3.
Most communications software applications default COM3: to IRQ4 and COM4: to IRQ3. This
requires the sharing of interrupts between COM1: and COM3:, and between COM2: and COM4:. While
this is the default, it is not always the preferred setting. Check your software configuration
instructions to determine the most appropriate IRQ selection.
Figure 3 - Header E6, IRQ Selection (Factory Default)
The actual Silk-Screen for the COMM+2 may have a “2” in place of the IRQ “2/9” selection.
2
/
9
3
4
5
2
/
9
3
4
5
Port 1
Port 2
E6

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
Any two or more ports can share a common IRQ, provided a proper interrupt sharing driver is used, by
placing the jumpers on the same IRQ setting at header E6, and setting the appropriate selections at E5.
Consult your particular software for IRQ selection. If no interrupt is desired, remove the jumper.
Interrupt Modes
Jumper block E5 allows you to select a single interrupt per port mode or a shared interrupt mode. The single
interrupt per port mode is the typical DOS, O/S 2 and Windows 3.X mode of operation.
The shared interrupt mode, which allows more than one port to access a single IRQ, indicates the inclusion
of a 1K ohm pull-down resistor required on one port when sharing interrupts. This mode is used by software
that requires COM3: and COM4: to share interrupts with COM1: and COM2: (see note on E6) or in an OEM
configuration to support a specific software application.
E5
Port 1 Port 2
Single Interrupt Mode
E5
Port 1 Port 2
Shared Interrupt Mode
Figure 4 - Header E5, IRQ Mode Selection

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
Headers E2 & E4
These jumper blocks make the connection between the UART pins and the actual driver/receiver pair that
are used. If you are using the RS-232 driver/receiver pair, all eight of these jumpers will be in the “A” position.
If you are using the RS-422 driver/receiver pair all eight of these jumpers will be in the “B” position.
Headers E1 & E3
These jumper blocks allow you to customize your interface in the following ways:
•Select if Modem control signals are used or tied “True”.
•Select the RS-485 enable option.
•Select whether the Ground connection is a Direct Ground or a High Impedance Ground
through a 100-ohm resistor.
E1 & E3
1"A" Selects RS-232 Receive Data; "B" Selects RS-422 Receive Data
2"A" Enables CTS; Remove to set Active
3"A" Enables DSR; "B" sets DSR Active
4"A" Enables DCD; "B" sets DCD Active
5"A" Enables RI; "B" Sets RI Active
6"A" Also required to Enable CTS; "B" Sets CTS Active
7"B" sets RS-485 Driver Enabled by RTS; "A" RS-485 Driver always Enabled 8"A" Selects Direct Ground; "B"
A | B Selects 100 ohm High Impedance Ground
Figure 5 - Header E1 and E3, Interface Selection Options
E1 & E3 E2 & E4 E1 & E3 E2 & E4 E1 & E3 E2 & E4
Figure 6 - Interface Option Examples
RS-232
RS-422
RS-485
A | B A | B
A | B A | B
A | B A | B

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
Installation
Do not install the hardware until the software has been fully installed.
The COMM+2 can be installed in any ISA PC expansion slot. The COMM+2 contains several jumper straps
for each port, which 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 slot and remove the blank metal slot cover.
4. Gently insert the COMM+2 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.
Operating System Installation
For Windows Users
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: SeaCOM Asynchronous
Serial Software.
2. Select “Download Now” for SeaCOM for Windows.
3. The setup files will automatically detect the operating environment and install the proper
components. Follow the information presented on the screens that follow.
4. A screen may appear with text similar to: “The publisher cannot be determined due to the
problems below: Authenticode signature not found.” Please click the ‘Yes’ button and
proceed with the installation. This declaration simply means that the operating system is
not aware of the driver being loaded. It will not cause any harm to your system.

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© Sealevel Systems, Inc. 3083 Manual | SL9107 1/2023
5. During setup, the user may specify installation directories and other preferred
configurations. This program also adds entries to the system registry that are necessary
for specifying the operating parameters for each driver. An uninstall option is also included
to remove all registry/INI file entries from the system.
To avoid accidental damage, be sure to follow the proper ESD procedures by grounding yourself
and the board.
Other Operating Systems
Refer to the appropriate section of the Serial Utilities Software.