Impulse 3055 User Manual
ULTRA 485™
USER MANUAL
Part #3055
Sealevel Systems, Inc. Telephone: (864) 843-4343
PO Box 830 Fax: (864) 843-3067
Liberty, SC 29657 USA www.sealevel.com
Contents
INTRODUCTION ........................................................................ 1
OVERVIEW......................................................................................1
WHAT’S INCLUDED.........................................................................1
FACTORY DEFAULT SETTINGS ........................................................1
CARD SETUP ............................................................................ 2
ADDRESS SELECTION......................................................................2
IRQ SELECTION..............................................................................3
INTERRUPT MODES.........................................................................4
RS-485 ENABLE MODES ................................................................5
CONNECTOR PIN ASSIGNMENTS......................................................7
EIA-530 ......................................................................................7
SIO-485.......................................................................................8
LINE TERMINATION ........................................................................9
INSTALLATION ....................................................................... 10
OPERATING SYSTEM INSTALLATION .............................................10
For Windows Users...................................................................10
Other Operating Systems ..........................................................10
TECHNICAL DESCRIPTION .................................................... 11
FEATURES.....................................................................................11
SPECIFICATIONS .................................................................... 12
ENVIRONMENTAL SPECIFICATIONS ...............................................12
MANUFACTURING.........................................................................12
POWER CONSUMPTION .................................................................12
MEAN TIME BETWEEN FAILURES (MTBF) ...................................12
PHYSICAL DIMENSIONS.................................................................12
APPENDIX A - TROUBLESHOOTING ...................................... 13
A
PPENDIX B - HOW TO GET ASSISTANCE............................ 15
APPENDIX C - ELECTRICAL INTERFACE .............................. 16
RS-530.........................................................................................16
RS-422.........................................................................................16
RS-485.........................................................................................17
APPENDIX D - ASYNCHRONOUS COMMUNICATIONS ............ 18
PPENDIX E - SILK-SCREEN ................................................. 19
A
APPENDIX F - COMPLIANCE NOTICES .................................. 20
FEDERAL COMMUNICATIONS COMMISSION STATEMENT...............20
EMC DIRECTIVE STATEMENT ......................................................20
WARRANTY............................................................................ 21
Figures
Figure 1 - Header E1, IRQ Selection........................................................3
Figure 2 - Header E2, Normal IRQ Mode................................................4
Figure 3 - Header E2, Shared IRQ Mode ................................................4
Figure 4 - Header E5 RS-485 Transmit Mode.........................................5
Figure 5 - Header E3 RS-485 Receive Mode ...........................................6
Figure 6 - DIP-shunt E4 (EIA-530 Mode)................................................7
Figure 7 - DIP-shunt E4 (SIO-485 Mode) ................................................8
Figure 8 - SW2, Line Termination............................................................9
Figure 9 - Asynchronous Communications Bit Diagram......................18
© Sealevel Systems, Inc.
SL9139 Revision 7/2006
Sealevel Systems, Incorporated. All rights reserved.
Introduction
Introduction
Overview
The Sealevel Systems ULTRA 485 provides the PC with an additional
RS-422/485 serial port for terminals, PLC communication, laboratory
instrumentation, etc.
The unique feature of the ULTRA 485 is the ability to be RS-485 compatible
without the need for special software or drivers. This is especially useful in
Windows, Windows NT, and OS/2 environments where the lower level I/O
control is abstracted from the application program. Which means that the user
can effectively use the ULTRA 485 in an RS-485 application with existing (i.e.
standard RS-232) software drivers.
What’s Included
The ULTRA 485 is shipped with the following items. If any of these items are
missing or damaged, contact the supplier.
• ULTRA 485 Serial I/O Adapter
• Sealevel Software
Factory Default Settings
The ULTRA 485 factory default settings are as follows:
Port # Base Address IRQ Electrical Specification
Port 1 280 5 RS-485 ‘Auto’
To install the ULTRA 485 using factory default settings, refer to Installation on
page 10.
For your reference, record installed ULTRA 485 settings below:
Port # Base Address IRQ Electrical Specification
Sealevel Systems ULTRA-485 Page 1
Card Setup
Card Setup
The ULTRA 485 contains several jumper straps that must be set for proper
operation.
Address Selection
The ULTRA 485 occupies 8 consecutive I/O locations, and looks to the PC as a
standard serial port. A DIP-switch (SW1) is used to set the port address options
for the ULTRA 485. Be careful when selecting the port addresses as some
selections may conflict with existing ports. The following table shows the
addressing options available with the standard PAL. If different address options
are required, please contact Sealevel Systems Technical Support about a custom
PAL option.
Port1 J2 SW1-1 SW1-2 SW1-3 SW1-4
Disabled On On On On
3F8 On On On Off
2F8 On On Off On
3E8 On On Off Off
2E8 On Off On On
3220 On Off On Off
3228 On Off Off On
4220 On Off Off Off
4228 Off On On On
238 Off On On Off
300 Off On Off On
308 Off On Off Off
280 Off Off On On
288 Off Off On Off
290 Off Off Off On
298 Off Off Off Off
Note: Each COM port in the system should have a unique address. Typically
COM1: - COM4: addresses are 3F8, 2F8, 3E8 & 2E8 Hex.
Sealevel Systems ULTRA-485 Page 2
Card Setup
IRQ Selection
Header E1 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.
Note: 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.
E1
2 3 4 5 7 10111215
Figure 1 - Header E1, IRQ Selection
Any two or more ports can share a common IRQ by placing the jumpers on the
same IRQ setting at header E1 and setting the appropriate selections at E2.
Consult your particular software for IRQ selection. If no interrupt is desired,
remove the jumper.
Sealevel Systems ULTRA-485 Page 3
Card Setup
Interrupt Modes
Header E2 selects the interrupt mode for the ULTRA 485.
‘N’ indicates the (N)ormal, single interrupt per port mode. ‘S’ Indicates the
(S)hared interrupt mode, which allows more than one port to access a single
IRQ. Any two or more ports can share a common IRQ by placing the jumpers on
the same IRQ setting and setting the appropriate selections at E1. Consult your
particular software for IRQ selection. If no interrupt is desired, remove the
jumper. ‘M’ indicates the inclusion of a 1K ohm pull-down resistor required on
one port when sharing interrupts.
Figure 2 - Header E2, Normal IRQ Mode
Set the jumper to ‘S’ if you are using more than one ULTRA 485 in a bus or to
completely remove the pull-down resistor for hardware compatibility. Setting
the adapter in this configuration when it is not accompanied by a pull-down
resistor will prevent the ports from triggering an interrupt.
Set the jumpers to ‘S’ for shared interrupt mode on all blocks sharing an IRQ
except one. Set that port block for ‘M’. This provides the pull-down resistor
circuit that makes sharing IRQs possible. If you are using more than one
ULTRA 485 or a compatible adapter in a bus you should only have one port set
to ‘M’. The following example shows two ULTRA 485 adapters sharing a
single IRQ.
Figure 3 - Header E2, Shared IRQ Mode
Sealevel Systems ULTRA-485 Page 4
Card Setup
RS-485 Enable Modes
RS-485 is ideal for multi-drop or network environments. RS-485 requires a
tri-state driver (not dual-state) 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 ULTRA 485 is the ability to be RS-485
compatible without the need for special software or drivers. This ability is
especially useful in Windows, Windows NT, and OS/2 environments where the
lower level I/O control is abstracted from the application program. This ability
means that the user can effectively use the ULTRA 485 in a RS-485 application
with existing (i.e. standard RS-232) software drivers.
Header E5 is used to control the RS-485 mode functions for the transmitter
circuit. The selections are ‘RTS’ enable, ‘Auto’ enable, or ‘422’ which means
always enabled. The ‘Auto’ enable feature automatically enables/disables the
RS-485 transmitter circuit. The ‘RTS’ mode uses the ‘RTS’ modem control
signal to enable the RS-485 transmitter circuit and provides backward
compatibility with existing software products. The ‘422’ mode allows the port to
be used in a point to point RS-422 application where the tri-stating of the
transmitter circuit is not required.
AUTO
E5
RTS
AUTO
RTS
422
422
TX
Driver automatically enabled/disabled
Driver enabled by UART RTS signal
Driver always enabled
Note: The jumper in the above example is in the ‘422’ position. This is the only
setting in which the modem control outputs (RTS, DTR) are valid.
Figure 4 - Header E5 RS-485 Transmit Mode
Sealevel Systems ULTRA-485 Page 5
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