Impulse 7404 User Manual
COMM+422.PCI
TM
USER MANUAL
Part # 7404
Sealevel Systems, Inc
P.O. Box 830
Liberty, SC 29657 USA
Phone: (864) 843-4343
FAX: (864) 843-3067
www.sealevel.com
Contents
INTRODUCTION ........................................................................ 1
OVERVIEW......................................................................................1
WHAT’S INCLUDED.........................................................................1
FACTORY DEFAULT SETTINGS ........................................................1
CARD SETUP ............................................................................ 2
RS-485 ENABLE MODES ................................................................2
Interface Mode Examples SW1 – SW4 (continued) ...................4
ADDRESS AND IRQ SELECTION.......................................................4
ELECTRICAL INTERFACE SELECTION...............................................5
CLOCK MODES ...............................................................................6
BAUD RATES AND DIVISOR S FOR THE ‘DIV1’ MODE ......................6
INSTALLATION ......................................................................... 7
OPERATING SYSTEM INSTALLATION ...............................................7
For Windows Users.....................................................................7
Other Operating Systems ............................................................7
SYSTEM INSTALLATION ..................................................................7
TECHNICAL DESCRIPTION ...................................................... 8
CONNECTOR PIN ASSIGNMENTS......................................................8
RS-422/485 (DB 9 Male)........................................................8
RS-232 (DB-9 Male)...............................................................8
SPECIFICATIONS ...................................................................... 9
ENVIRONMENTAL SPECIFICATIONS .................................................9
MANUFACTURING...........................................................................9
POWER CONSUMPTION ...................................................................9
MEAN TIME BETWEEN FAILURES (MTBF) .....................................9
PHYSICAL DIMENSIONS ...................................................................9
PPENDIX A - TROUBLESHOOTING ...................................... 10
A
APPENDIX B - HOW TO GET ASSISTANCE............................ 11
APPENDIX C - ELECTRICAL INTERFACE .............................. 12
RS-232.........................................................................................12
RS-422.........................................................................................12
RS-485.........................................................................................13
APPENDIX D - ASYNCHRONOUS COMMUNICATIONS ............ 14
APPENDIX E - SILK-SCREEN ................................................. 15
APPENDIX F - COMPLIANCE NOTICES .................................. 16
FEDERAL COMMUNICATIONS COMMISSION STATEMENT...............16
EMC DIRECTIVE STATEMENT ......................................................16
WARRANTY............................................................................ 17
Figures
Figure 1- Switches SW1- SW4, RS-422 ....................................................3
Figure 2 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘No Echo’ and
the termination resistor in circuit. ....................................................3
Figure 3 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘Echo’ and no
termination resistor in circuit. ..........................................................3
Figure 4 - Switches SW1- SW4, RS-485 ‘RTS’ Enabled, with ‘No Echo’ and
no termination resistor in circuit. .....................................................4
Figure 5 - Switches SW1- SW4, RS-485 ‘RTS’ Enabled, with ‘Echo’ and no
termination resistor in circuit. ..........................................................4
Figure 6 - Asynchronous Communications Bit Diagram......................14
© Sealevel Systems, Inc.
SL9064 Revision 7/2006
Sealevel Systems, Incorporated. All rights reserved.
Introduction
Introduction
Overview
The Sealevel COMM+4.PCI is a four channel RS-232/485/422 PCI Bus serial
I/O adapter supporting data rates up to 460.8K bps.
The RS-232 compatibility allows for connection to devices utilizing the RS-232
electrical interface, such as modems, data-entry terminals, and plotters.
RS-422 provides excellent communications for long distance device connections
up to 4000ft., 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).
In both RS-485 and RS-422 modes, the card works seamlessly with the standard
operating system serial driver. In RS-485 mode, our special auto-enable feature
allows the RS-485 ports to be viewed by the operating system as a COM: port.
This allows the standard COM: driver to be utilized for RS-485 communications.
Our on-board hardware automatically handles the RS-485 driver enable.
What’s Included
The COMM+4.PCI is shipped with the following items. If any of these items is
missing or damaged, contact the supplier.
• COMM+4.PCI Serial I/O Adapter
• Sealevel Software
• “Spider” Cable providing 4 DB-9 connectors
Factory Default Settings
The COMM+4.PCI factory default settings are as follows:
Port # Clock DIV Mode Enable Mode
Port 1 4 RS-422
Port 2 4 RS-422
Port 3 4 RS-422
Port 4 4 RS-422
To install the COMM+4.PCI using factory default settings, refer to Installation
on page 7.
Sealevel Systems COMM+4.PCI Page 1
Card Setup
Card Setup
RS-485 Enable Modes
RS-485 is ideal for multi-drop or network environments. RS-485 requires a
tri-state driver that will allow the electrical presence of the driver to be removed
from the line. The driver is in a tri-state or high impedance condition when this
occurs. Only one driver may be active at a time and the other driver(s) must be
tri-stated. The output modem control signal Request To Send (RTS) is typically
used to control the state of the driver. Some communication software packages
refer to RS-485 as RTS enable or RTS block mode transfer.
One of the unique features of the COMM+4.PCI is the ability to be RS-485
compatible without the need for special software or drivers. This ability is
especially useful in Windows and other protected mode environments where the
lower level I/O control is abstracted from the application program. This ability
means that the user can effectively use the COMM+4.PCI in an RS-485
application with existing (i.e. standard RS-232) software drivers.
Switches SW1 - SW4 are used to control the RS-485 mode functions for the
driver circuit. The selections are ‘RTS’ enable (silk-screen ‘RT’) or ‘Auto’
enable (silk-screen ‘AT’). The ‘Auto’ enable feature automatically
enables/disables the RS-485 interface. The ‘RTS’ mode uses the ‘RTS’ modem
control signal to enable the RS-485 interface and provides backward
compatibility with existing software products.
Position 3 (silk-screen ‘NE’) of these switches is used to control the RS-485
enable/disable functions for the receiver circuit and determine the state of the
RS-422/485 driver. 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. This can be beneficial if the software can handle echoing (i.e. using
received characters to throttle the transmitter) or it can confuse the system if the
software does not. To select the ‘No Echo’ mode select silk-screen position
‘NE’.
Typically, each end of the RS-485 bus must have a line-terminating resistor
(RS-422 terminates the receive end only). 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. Only the ends of an RS-485 network should have the
120-Ohm terminating resistor. Position 4 (silk-screen ‘T’) selects the presence of
the 120-Ohm termination resistor across the input data pins (RX+/RX-). To add
the termination select the ‘On’ position, to remove it select the ‘Off’ position.
For RS-422/530/449 compatibility set all switches ‘Off’. Examples on the
following pages describe some of the valid settings for SW1-SW4.
Sealevel Systems COMM+4.PCI Page 2
Card Setup
Interface Mode Examples SW1 – SW4
ON
OFF
1 2 3 4
AT RT NE T
Figure 1- Switches SW1- SW4, RS-422
ON
OFF
1 2 3 4
AT RT NE T
Figure 2 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘No Echo’ and the
termination resistor in circuit.
ON
OFF
1 2 3 4
AT RT NE T
Figure 3 - Switches SW1- SW4, RS-485 ‘Auto’ Enabled, with ‘Echo’ and no
termination resistor in circuit.
Sealevel Systems COMM+4.PCI Page 3
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