Manual - ADL Embedded Solutions
Embedded Solutions
MODEL USB-FLEXCOM4
USB to Four RS-232/422/485 Serial Ports
and
MODEL USB-COM232-4A
USB to Four RS-232 Serial Ports
USER MANUAL
FILE: MUSB-FLEXCOM4.B1f
ADL Embedded Solutions GmbH, Eiserfelder Straße 316 D-57080 Siegen,
Germany P. +49 (0) 271 250 810 0 F. +49 (0) 271 250 810 20
e-mail: sales@adl-europe.com; web: www.adl-europe.com
ADL Embedded Solutions Inc., 4411 Morena Blvd., Suite 101
San Diego, CA 92117-4345 P. +1 858 490-0597 F. +1 858 490-0599
e-mail: sales@adl-usa.com; web: www.adl-usa.com
Notice
The information in this document is provided for reference only. ADL Embedded Solutions Inc. does not
assume any liability arising out of 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 ADL Embedded Solutions Inc., nor the rights of others.
IBM PC, PC/XT, and PC/AT are registered trademarks of the International Business Machines Corporation.
Printed in USA. Copyright 2001, 2006 by ADL Embedded Solutions Inc., 4411 Morena Blvd. Suite 101, San
Diego, CA 92117. All rights reserved.
WARNING!!
ALWAYS CONNECT AND DISCONNECT YOUR FIELD CABLING WITH THE
COMPUTER POWER OFF. ALWAYS TURN COMPUTER POWER OFF
BEFORE INSTALLING A BOARD. CONNECTING AND DISCONNECTING
CABLES, OR INSTALLING BOARDS INTO A SYSTEM WITH THE
COMPUTER OR FIELD POWER ON MAY CAUSE DAMAGE TO THE I/O
BOARD AND WILL VOID ALL WARRANTIES, IMPLIED OR EXPRESSED.
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Manual USB-FLEXCOM4
Table of Contents
Chapter 1: Introduction..................................................................................................................................... 4
Features .......................................................................................................................................................... 4
Applications ................................................................................................................................................... 4
Functional Description.................................................................................................................................. 4
RS422 Balanced Mode Operation............................................................................................................. 4
RS485 Balanced Mode Operation............................................................................................................. 4
COM Port Compatibility............................................................................................................................. 5
Communication Mode................................................................................................................................ 5
Figure 1-1: Block Diagram (Only one full serial channel shown) ................................................................ 6
Baud Rates ................................................................................................................................................. 6
Ordering Guide .............................................................................................................................................. 7
Model Options ............................................................................................................................................ 7
Special Order.............................................................................................................................................. 7
Included with your board .......................................................................................................................... 7
Optional AccessoriesSample Programs ................................................................................................... 12
Figure 5-1: WinRISC Windows Terminal Program Screen Shot .............................................................. 12
Chapter 6: Connector Pin Assignments ....................................................................................................... 13
Table 6-1: DB9M Connector Pin Assignments.......................................................................................... 13
Table 6-2: 10-Pin Header Connector Pin Assignments ............................................................................ 13
Chapter 7: Specifications ............................................................................................................................... 14
Appendix A: Application Considerations ..................................................................................................... 15
Table A-1: Connections Between Two RS422 Devices............................................................................ 15
Table A-2: RS485 Data Cable Wiring ....................................................................................................... 15
Table A-2: RS422/485 Specification Summary......................................................................................... 16
RS485 Data Transmission........................................................................................................................... 16
Figure A-1: Typical RS485 Two-Wire Multidrop Network ......................................................................... 17
..................................................................................................................................................................... 7
Figure 1-2: ADAP9 Screw Terminal Accessory .......................................................................................... 7
Chapter 2: Installation....................................................................................................................................... 8
Software CD Installation ............................................................................................................................... 8
Installing the Adapter .................................................................................................................................... 8
Chapter 3: Hardware Details ............................................................................................................................ 9
Option Selection ............................................................................................................................................ 9
Figure 3-1: Jumper Labels .......................................................................................................................... 9
Terminations .................................................................................................................................................. 9
Figure 3-2: Simplified Termination Schematic ............................................................................................ 9
Figure 3-3: Option Selection Map ............................................................................................................. 10
Default Shipping Configuration ................................................................................................................. 10
Connectors and Indicator Functions......................................................................................................... 10
Chapter 4: USB Address Information............................................................................................................ 11
Address Map ................................................................................................................................................ 11
Chapter 5: Programming ................................................................................................................................ 12
Customer Comments ...................................................................................................................................... 19
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Manual USB-FLEXCOM4
Chapter 1: Introduction
This flexible serial communications adapter was designed for effective multipoint transmission in any
one of three modes on each channel. These modes are RS232, RS422 and RS485 (EIA485) protocol.
Features
•
•
•
•
•
•
•
Four-port serial communications adapter for USB 1.1 and USB 2.0 host ports
Supports field selectable RS-232, RS-422 or RS-485 protocols, per port
Includes type FT232BM UART with 384-byte receive/128-byte transmit FIFO buffers
Speeds up to 921.6kbps simultaneously
Power LED and individual port activity LEDs visible next to the USB and each COM connector
All required power drawn from USB port, no external power adapter required
Compact, low profile enclosure
Applications
Multiple peripherals such as POS, barcode scanners, scales, date-entry terminals, data acquisition
modules, and automation equipment will benefit from the small size, low cost, reliability and simplicity
of this product.
Functional Description
RS422 Balanced Mode Operation
The board supports RS422 communications and uses differential balanced drivers for long range and
noise immunity. The board also has the capability to add load resistors to terminate the communications
lines. RS422 communications requires that a transmitter supply a bias voltage to ensure a known "zero"
state. Also, receiver inputs at each end of the network should be terminated to eliminate "ringing". The
board supports biasing by default and supports termination by jumpers on the card. If your application
requires the transmitter to be un-biased, please call us.
RS485 Balanced Mode Operation
The board supports RS485 communications and uses differential balanced drivers for long range and
noise immunity. RS485 operation involves switchable transceivers and the ability to support multiple
devices on a single "party line". The RS485 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".
This board also has the capability to add load resistors to terminate the communications lines. RS485
communications requires 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 card supports biasing by default and supports termination by jumpers on the
card. If your application requires the transmitter to be un-biased, please call us.
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Manual USB-FLEXCOM4
COM Port Compatibility
The FT232BM UARTs are used as Asynchronous Communication Elements (ACE). These include 128byte transmit & 384-byte receive buffers to protect against lost data in multitasking operating systems,
while maintaining 100 percent compatibility with the original IBM serial port. The system assigns the
COM numbers automatically.
The driver/receiver used (SP491 in non-RS232 modes) 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 to -7 V. In case of
communication conflict, the driver/receivers feature thermal shutdown.
The driver/receiver used in RS232 mode is the ICL3243.
Communication Mode
The board supports Half-Duplex communications with a 2-wire cable connection. Half-Duplex allows
traffic to travel in both directions, but only one way at a time. RS485 communications commonly use the
Half-Duplex mode since they share only a single pair of wires.
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Manual USB-FLEXCOM4
Figure 1-1: Block Diagram (Only one full serial channel shown)
Baud Rates
Baud rates up to 921.6kbps are supported in RS-422 and RS-485 modes while RS-232 has a limit of
230.4kbps.
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Manual USB-FLEXCOM4
Ordering Guide
USB-FLEXCOM4
USB to four port RS-232/422/485 serial adapter
USB-COM232-4A
USB to four port RS-232 serial adapter
Model Options
•
•
•
•
-OEM
-HDR
-DIN
-RoHS
Board only version with no enclosure
10-pin male headers onboard instead of DB9 connectors (only available on OEM version)
DIN rail mounting bracket for integrating into legacy and industrial environments
This product is available in a RoHS compliant version. Please call for specific pricing then be
sure to add this suffix to the model number on any hard-copy or verbal purchase orders.
Special Order
Custom baud rates are achievable by using a different crystal oscillator. Contact factory with your
requirement. Other examples of special orders would be conformal coating, un-biased transmitter
lines, etc.
Included with your board
The following components are included with your shipment, depending on options ordered. Please
take the time now to ensure that no items are damaged or missing.
•
•
•
•
USB Module in labeled enclosure with an anti-skid bottom
6' USB 2.0 cable
Software Master CD
USB I/O Quick-Start Guide
Optional Accessories
•
•
•
•
C104-10F-12
STB-10
DIN-SNAP6
ADAP9
Ribbon Cable Assembly, 12” with 10 pin female headers on each end
Screw Terminal Board, 10 pin male header
DIN-rail mounting for one STB-10
Screw Terminal Adaptor board with a Male DB9 connector and 9 screw terminals
Figure 1-2: ADAP9 Screw Terminal Accessory
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Manual USB-FLEXCOM4
Chapter 2: Installation
A printed USB I/O Quickstart Guide is normally included and packed with your hardware for shipment.
It provides all the straight-forward steps necessary to complete your software and hardware
installation.
Software CD Installation
The software provided with this board is contained on one CD and must be installed onto your
hard disk prior to use. To do this, perform the following steps as appropriate for your operating
system. Substitute the appropriate drive letter for your drive where you see d: in the examples below.
WIN98/Me/2000/XP/2003
1.
Place the CD into your CD-ROM drive.
2.
The install program should automatically run. If not click START | RUN and type
GLQVWDOO, click OK or press ..
3.
Follow the on-screen prompts to install the software for this board.
4.
Leave the CD in the drive as it may be needed for driver installation once you plug the hardware
into the USB port.
Installing the Adapter
Before installing the adapter, carefully read the OPTION SELECTION section of this manual and
configure the adapter according to your requirements. In Windows, the SETUP.EXE program will lead
you through the process of setting the options on the board. The setup program does not set the
options. These must be set manually by jumpers on the board, within the case of the adapter.
To Install the Adapter
1.
2.
3.
4.
5.
Remove the four screws on the sides of the enclosure. Slide the lid to one side then pull the
side of the lid out to clear the DB9 connectors. Once cleared, pull the cleared side of the lid
upward to remove it.
Print the Option Selection Map to make notes on. Determine what protocol each port (A-D)
will communicate in (RS232, RS422 or RS485 etc.). Record these details on your printout.
Install jumpers for each port following either the Option Selection section of this manual or the
suggestions of the SETUP.EXE software program.
Re-install the lid and four screws.
Plug the USB cable into the device and the USB port then follow the new hardware wizard to
complete driver installation.
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Manual USB-FLEXCOM4
Chapter 3: Hardware Details
Option Selection
To help you locate the jumpers described in this section, refer to the Option Selection Map at the end of
this section. Operation of the serial communications is determined by jumper installation as described in
the following paragraphs. For the convenience of the user, the jumpers are clearly labeled as follows:
Figure 3-1: Jumper Labels
Terminations
A transmission line should be terminated at the receiving end in its characteristic impedance. Installing a
jumper at the locations labeled TERM applies a 120Ω load across the receive input for RS-422 and the
transmit/receive input/output for RS485 operation.
Tx+/R x+
RS485 Term
120
0.01 µF
Tx-/R x-
Figure 3-2: Simplified Termination Schematic
In RS485 operations where there are typically multiple terminals, only the RS485 devices at each end of
the network (the serial COM port at one end and an RS-485 device at the other end) should have
terminating impedance as described above. Refer to Appendix A: Application Considerations for further
explanations and diagrams of typical RS-485 networks.
To terminate the COM A port, place a jumper at the location labeled TERM in the jumper cluster near
J1. To terminate the COM B, COM C or COM D ports, place jumpers at locations labeled TERM near J2
(COM B), J3 (COM C) or J4 (COM D) respectively.
Also, for RS485 operation, there must be a bias on the TRX+ and TRX- lines which this adapter
provides. If the adapter is not to provide that bias, contact the factory for technical support.
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Manual USB-FLEXCOM4
Figure 3-3: Option Selection Map
The board has 4 separate channels which are individually configured. Each channel can be used in one
of four modes. Install jumpers referring to the Option Selection Map above for guidance.
1) RS232 - Install the 2-position jumper in the 232 position.
2) RS422 - Install the 2-position jumper in the 422/485 position.
3) RS485 (4 wire) – It is assumed that this unit will function as the “Master” in 4-wire RS485
mode. In this case configure the jumpers for RS422. It is also possible to
use it as a “Slave”. In this case, install the 2-position jumper in the 422/485
position and install the 485TX jumper.
4) RS485 (2 wire) - Install the 2-position jumper in the 422/485 position, install the 485TX and
485RX jumpers, and install both the TxRx+ jumper and the TxRx- jumper.
5) To provide a termination load for RS422 or RS485, install the TERM jumper for that channel.
Note: Any unneeded jumpers that are installed can cause the adapter to function incorrectly.
Default Shipping Configuration
This communications adapter ships with each port configured for RS485 two-wire mode. If you need to
communicate in any other of the supported modes, you’ll need to remove the lid and configure the
jumpers for that port.
Connectors and Indicator Functions
USB Connector
Embedded USB Connector
LED near USB connector
LEDs and DB9 Connectors
Type B, high-retention design
Mini 5-pin header in parallel with type B connector
Indicates power and activity
COM activity indicator next to each COM port connector
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Manual USB-FLEXCOM4
Chapter 4: USB Address Information
Use the provided driver to access the USB board. This driver will allow you to determine how many supported
USB devices are currently installed, and each device’s type.
Address Map
The core of the UART function is supplied by the FTDI FT232BM chip.
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Manual USB-FLEXCOM4
Chapter 5: Programming
Sample Programs
There are sample programs provided with the board in several Windows languages. Windows samples
are located in the WIN32 directory.
Figure 5-1: WinRISC Windows Terminal Program Screen Shot
Windows Programming
►
►
►
The board installs into Windows as COM ports. Thus the Windows standard API functions can be used.
In particular:
CreateFile() and CloseHandle() for opening and closing a port.
SetupComm(), SetCommTimeouts(), GetCommState(), and SetCommState() to set and change a
port’s settings.
ReadFile() and WriteFile() for accessing a port.
See the documentation for your chosen programming language for details.
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Manual USB-FLEXCOM4
Chapter 6: Connector Pin Assignments
Input/Output Connections
The Serial Communications board uses four individual DB9 connectors. The –OEM version is available
with an option for 10-pin headers as the –HDR. The second table lists pin connections for the –HDR
version.
Proper EMI cabling techniques include using shielded twisted-pair wiring for the input/output wiring.
Anywhere there is no signal listed means “make no connection”.
DB-9 Male Pin for
each of Ch A-D
Ch x - 1
Ch x - 2
Ch x - 3
Ch x - 4
Ch x - 5
Ch x - 6
Ch x - 7
Ch x - 8
Ch x - 9
RS-232 Signals
(Industry Standard)
DCD
RX
TX
DTR
Gnd
DSR
RTS
CTS
RI
RS-485 Signals
(2 Wire)
TX+/RX+
TX-/RX-
RS-422 Signals
(Also 4wire RS485)
RXTX+
TX-
Gnd
Gnd
RX+
Table 6-1: DB9M Connector Pin Assignments
10-Pin header for each
of Ch A-D
Ch x - 1
Ch x – 3
Ch x – 5
Ch x – 7
Ch x – 9
Ch x – 2
Ch x – 4
Ch x – 6
Ch x – 8
Ch x - 10
RS-232 Signals
(Industry Standard)
DCD
RX
TX
DTR
Gnd
DSR
RTS
CTS
RI
RS-485 Signals
(2 Wire)
TX+/RX+
TX-/RX-
RS-422 Signals
(Also 4wire RS485)
RXTX+
TX-
Gnd
Gnd
RX+
Table 6-2: 10-Pin Header Connector Pin Assignments
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Manual USB-FLEXCOM4
Chapter 7: Specifications
Communications Interface
•
Serial Ports:
COM A through COM D via four male DB9 connectors
•
Character length:
5, 6, 7, or 8 bits
•
Parity:
Even, odd or none
•
Stop Interval:
1, 1.5, or 2 bits
•
Serial Data Rates:
Up to 921.6k for RS-422 and RS-485 modes, asynchronous
RS-232 speeds up to 230.4kbps.
•
Receiver Input Sensitivity:
+200 mV, differential input
•
Common Mode Rejection:
+12V to -7V
•
Transmitter Output Drive:
Up to 60 mA, with thermal shutdown
Bus Type
USB 2.0 Full-Speed
•
USB Connector:
Type B, high-retention
•
Embedded USB Connector 5-pin header, Molex part number 53047
Mating connector housing is Molex part number 51021 0500
Environmental
•
Operating Temperature:
0 °C. to +60 °C
•
Storage temperature:
-50 °C. to +120 °C
•
Humidity:
5% to 95%, non-condensing
•
Power Required:
5VDC at approximately 110 mA (plus loads up to an additional 240 mA) from
USB bus
•
Size:
Board Dimension: 3.550 x 3.775 inches (PC/104 size & mounting)
Box Dimension: 4.00 x 4.00 x 1.25 inches
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Manual USB-FLEXCOM4
Appendix A: Application Considerations
Introduction
Working with RS422 and RS485 devices is not much different from working with standard RS232 serial
devices and these two standards overcome deficiencies in the RS232 standard. First, the cable length
between two RS232 devices must be short; less than 50 feet at 9600 baud. Second, many RS232
errors are the result of noise induced on the cables. The RS422 and RS485 standards permit cabling up
to 5000 feet and since it operates in differential mode, is more immune to induced noise.
Connections between two RS422 devices (with CTS ignored) should be as follows:
Device #1
Device #2
Signal
Pin No.
Signal
Pin No.
Gnd
5
Gnd
5
TX+
2
RX+
9
TX-
3
RX-
1
RX+
9
TX+
2
RX-
1
TX-
3
Table A-1: Connections Between Two RS422 Devices
A third deficiency of RS232 is that more than two devices cannot share the same cable. This is also true
for RS422 but RS485 offers all the benefits of RS422 plus allows up to 32 devices to share the same
twisted pairs. An exception to the foregoing is that multiple RS422 devices can share a single cable if
only one will talk and the others will all receive.
SERIAL PORT CONNECTOR
CABLE TO RS-485 DEVICE
Signal
Pin No.
Signal
Pin No.
Tx/Rx+
2
Tx/Rx +
2
Tx/Rx -
3
Tx/Rx -
3
100 Ω to Ground
5
100 Ω to Ground
5
Table A-2: RS485 Data Cable Wiring
Balanced Differential Signals
The reason that RS422 and RS485 devices can drive longer lines with more noise immunity than
RS232 devices is that a balanced differential drive method is used. In a balanced differential system,
the voltage produced by the driver appears across a pair of wires. A balanced line driver will produce a
differential voltage from +2 to +6 volts across its output terminals. A balanced line driver can also have
an input "enable" signal that connects the driver to its output terminals. If the "enable signal is OFF, the
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Manual USB-FLEXCOM4
driver is disconnected from the transmission line. This disconnected or disabled condition is usually
referred to as the "tristate" condition and represents a high impedance. RS485 drivers must have this
control capability. RS422 drivers may have this control but it is not always required.
A balanced differential line receiver senses the voltage state of the transmission line across the two
signal input lines. If the differential input voltage is greater than +200 mV, the receiver will provide a
specific logic state on its output. If the differential voltage input is less than -200 mV, the receiver will
provide the opposite logic state on its output. A maximum operating voltage range is from +6V to -6V
allows for voltage attenuation that can occur on long transmission cables.
A maximum common mode voltage rating of +7V provides good noise immunity from voltages induced
on twisted pair lines. A signal ground connection is necessary to keep common mode voltage within that
range. The circuit may operate without the ground connection but may not be reliable.
Parameter
Conditions
Driver Output Voltage (unloaded)
Driver Output Voltage (loaded)
TERM
jumper in
Min.
Max.
4V
6V
-4V
-6V
2V
-2V
Driver Output Resistance
50Ω
Driver Output Short-Circuit Current
+150 mA
Driver Output Rise Time
10% unit interval
Receiver Sensitivity
+200 mV
Receiver Common Mode Voltage Range
+7V
Receiver Input Resistance
4KΩ
Table A-2: RS422/485 Specification Summary
To prevent signal reflections in the cable and to improve noise rejection in both the RS422 and RS485
mode, the receiver end of the cable should be terminated with a resistance equal to the characteristic
impedance of the cable. (An exception to this is the case where the line is driven by an RS422 driver
that is never "tristated" or disconnected from the line. In this case, the driver provides a low internal
impedance that terminates the line at that end.)
Note
You do not have to add a terminator resistor to your cables when you use the adapter. Termination
resistors for the RX+ and RX- lines are provided on the card and are placed in the circuit when you
install the RS 485 jumpers. (See the Option Selection section of this manual.)
RS485 Data Transmission
The RS485 Standard allows a balanced transmission line to be shared in a party-line mode. As many as
32 driver/receiver pairs can share a two-wire party line network. Many characteristics of the drivers and
receivers are the same as in the RS422 Standard. One difference is that the common mode voltage limit
is extended and is +12V to -7V. Since any driver can be disconnected (or tristated) from the line, it must
withstand this common mode voltage range while in the tristate condition.
The following illustration shows a typical multidrop or party line network. Note that the transmission line
is terminated on both ends of the line but not at drop points in the middle of the line.
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Manual USB-FLEXCOM4
Figure A-1: Typical RS485 Two-Wire Multidrop Network
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Manual USB-FLEXCOM4
RS485 Four-Wire Multidrop Network
An RS485 network can also be connected in a four-wire mode. In a four-wire network it's necessary that
one node be a master node and all others be slaves. The network is connected so that the master
transmits to all slaves and all slaves transmit to the master. This has advantages in equipment that uses
mixed protocol communications. Since the slave nodes never listen to another slave's response to the
master, a slave node cannot reply incorrectly.
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Manual USB-FLEXCOM4
Customer Comments
If you experience any problems with this manual or just want to give us some feedback, please email us at:
sales@adl-usa.com or sales@adl-europe.com. Please detail any errors you find and include your mailing
address so that we can send you any manual updates.
Embedded Solutions
ADL Embedded Solutions GmbH, Eiserfelder Straße 316 D-57080 Siegen,
Germany P. +49 (0) 271 250 810 0 F. +49 (0) 271 250 810 20
e-mail: sales@adl-europe.com; web: www.adl-europe.com
ADL Embedded Solutions Inc., 4411 Morena Blvd., Suite 101
San Diego, CA 92117-4345 P. +1 858 490-0597 F. +1 858 490-0599
e-mail: sales@adl-usa.com; web: www.adl-usa.com
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Manual USB-FLEXCOM4
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