CommTech Fastcom G422/4-PCIe Quick user guide

Fastcom®: G422/X-PCIe
9011 E. 37TH STREET N
WICHITA, KANSAS 67226-2006
[phone]
FAX [phone]
http://www.commtech-fastcom.com/
COPYRIGHT (C) 2013
All rights reserved, including those to reproduce this document or parts thereof in
any form without permission in writing from Commtech, Inc.
FASTCOM and the “Alpha Lemur” are registered trademarks of Commtech, Inc.
Microsoft is a registered trademark of Microsoft Corporation.
WINDOWS is a trademark of Microsoft Corporation.

Fastcom®: G422/X-PCIe
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Fastcom®: G422/X-PCIe
TABLE OF CONTENTS
INTRODUCTION .......................................................................................................................5
SPECIFICATIONS........................................................................................................................6
FEATURES ................................................................................................................................6
BOARD LAYOUT......................................................................................................................7
INSTALLATION.........................................................................................................................8
HARDWARE INSTALLATION..........................................................................................................8
SOFTWARE INSTALLATION ..........................................................................................................8
TESTING THE INSTALLATION................................................................................................8
TESTING THE FASTCOM ASYNC PCI PORT IN WINDOWS ...............................................................8
FASTCOM SERIALFC SETTINGS .........................................................................................10
FASTCOM: G422/X-PCIE ADAPTER CABLE........................................................................12
CHAMP68 PIN DESCRIPTION ..................................................................................................12
DB9 PIN DESCRIPTION ............................................................................................................13
CABLE....................................................................................................................................13
PROGRAMMING.....................................................................................................................14
RS422 / RS485........................................................................................................................15
TERMINATION RESISTANCE ......................................................................................................16
RS-485 MODE........................................................................................................................17
TECHNICAL SUPPORT..........................................................................................................18
APPENDIX A...........................................................................................................................19
17V354 &17V358 UART DATA SHEET ...................................................................................19

5
Fastcom®: G422/X-PCIe
INTRODUCTION
The Fastcom PCIe bus, asynchronous RS-422/485 adapters utilize the latest technology to live up to today’s
requirements for high bandwidth in communication systems. The Fastcom: 422/4-PCIe and 422/8-PCIe (referred
to hereafter as Fastcom: G422/X-PCIe) are capable of operating at virtually any baud rate up to an astounding
maximum serial data rate of 25 Mbps. There is no fine print or asterisks pointing to notes; this card is capable of
running at the maximum data rate, without any jumpers or hardware changes, right out of the box.
The Fastcom: G422/X-PCIe adapters utilize an advanced quad Universal Asynchronous Receiver and
Transmitter (UART). Each channel of the 17V35x UART is independently controlled and has its own 16C550
compatible register set. Each UART contains its own receive and transmit FIFOs of 256 bytes with
programmable trigger levels.
Each of the UART channels on the board can be independently configured as either RS-422 or RS-485 for full or
half-duplex communication. This is implemented using an automatic RS-485 transmitter enable/disable function
that permits the hardware itself to regulate data flow by only driving lines while actively transmitting. This provides
increased speed and convenience over the older software controlled method, while still allowing the use of the
software method of flow control. Optionally, in automatic RS-485 mode, the receiver can be disabled during
transmits to avoid a receive echo, common in 2-wire 485 networks.
Additionally, each board utilizes a programmable clock generator to create the UART’s input frequency. The
clock generator is capable of generating frequencies between 6 and 50 MHz. Utilizing this feature, it is possible
to configure the board to operate at virtually any serial data rate that the user desires (up to 25 Mbits/second
maximum).
With the supplied software driver, the ports on the Fastcom: G422/X-PCIe cards will be seen as standard COM
ports and can utilize all the same functions as a standard serial device. With the addition of a few simple I/O
commands to control the unique features of the board, the standard software interface to a serial port can be used
to simplify program design. C, C++, .NET and python libraries are provided to demonstrate how to effectively use
the serial interface as well as control the board-specific features.
Overall, the Fastcom: G422/X-PCIe RS-422/485 adapters are ideal for commercial and industrial applications
demanding high data rates, reliability and ease of use.
Software drivers for Windows XP through Windows 8 and Linux are supplied. Multiple Fastcom: G422/X-PCIe
adapters can be installed in all operating systems.

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Fastcom®: G422/X-PCIe
Specifications
UART:
Exar 17V354 or Exar 17V358
OS Support:
Windows XP through Windows 8, Linux
Data Rates:
All baud rates up to 25Mbits/second
Buffering:
256 byte Tx FIFO each channel
256 byte Rx FIFO each channel
Drivers/Receivers:
High Speed RS-422
Interface:
RS-422 / RS-485
Signals:
Tx , Rx , RTS , CTS
Connector Configuration:
CHAMP 68 male to 4 DB9 female for 422/4-PCIe
CHAMP 68 male to 8 DB9 female for 422/8-PCIe
Bus Interface:
PCIe 2.0 Gen 1 (x1)
Power Requirements:
200mA @ +3V (typical)
Operating Temperature Range:
0 C to 70 C
Humidity:
0 to 90% (non-condensing)
Features
New high performance UART
All baud rates up to 25 Mbits/second
256 byte FIFO for improved throughput
Four independent channels
Hardware control for 485 drivers
Software-programmable baud rates
Switchless design for durability and reliability
Status LEDs for system development / debugging
Hardware Rx echo cancel available in RS-485 mode
Software enabling/disabling termination resistors
Durable cables with RFI shielding
Hardware documentation, software, and example programs provided on the Fastcom CD
Made in Wichita, Kansas, USA

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Fastcom®: G422/X-PCIe
BOARD LAYOUT
PACKING LIST
Fastcom: G422/X-PCIe Card
G422/X-PCIe Cable Assembly
Fastcom CD
If an omission has been made, please call customer service at 316-636-1131 for a replacement.

8
Fastcom®: G422/X-PCIe
INSTALLATION
Hardware Installation
Important: Static electricity can harm system boards. Perform service at an ESD workstation and follow
proper ESD procedures to reduce the risk of damage to components. Commtech, Inc. strongly
encourages you to follow proper ESD procedures, which can include wrist straps and smocks, when
handling Fastcom: G422/X-PCIe boards.
1. Turn off PC power. Disconnect the power cord.
2. Remove the PC case cover (if applicable).
3. Unpack the Fastcom: G422/X-PCIe.
4. Select an open PCIe slot in your PC.
5. After removing the blank bracket from your PC, install the Fastcom: G422/X-PCIe in the PC by pressing it
firmly into the slot. Install the bracket screw to hold it firmly in place.
6. Re-install the cover on your PC (if applicable).
7. Refer to Software Installation in the next section for information on installing the software for the board.
Software Installation
The software installation manual is in a separate document. The procedure changes from time to time as we
make improvements.
TESTING THE INSTALLATION
To fully test the installation of your Fastcom: G422/X-PCIe, you will need to build a "loop back plug". Materials
needed are a DB9 male plug, solder-cup style, and two short pieces of 20 or 24 AWG stranded wire. This loop
back plug can be used to test any RS-422 port. Jumper the pins together on the DB9 as illustrated below:
Pin 4 Tx +
Pin 5 Tx -
Pin 8 Rx +
Pin 9 Rx -
Testing the Fastcom Async PCI Port in Windows
These instructions assume that you have already installed the card and have followed the installation instructions.
The Device Manager should show the boards/ports that are installed, and the COM numbers assigned to those
ports.
5
48
9

9
Fastcom®: G422/X-PCIe
1. Attach the supplied G422/X-PCIe Cable Assembly to the CHAMP 68 connector. Install the loopback plug
on the port to test.
2. Open a Command prompt window and change to the directory (C:\> cd directoryname ) where
you saved the Fastcom software files that were either copied from the CD or downloaded from our
website. Change to the examples directory, then change to the loop directory.
3. Type: loop X Where X is the COM port you wish to test.
4. This test will transmit data out of the specified COM port and receive the data on the same port, checking
to see that the data is still the same.
If you get error messages during the loop test, some possible reasons are:
1. You have an incorrect or faulty loop back plug construction or a bad connection. Verify the wiring is
correct in your plug and correct any problems you may find.
2. The Fastcom board did not install correctly. Open the Device Manager (Start -> Run -> devmgmt.msc ->
OK). Expand the “Multi-port serial adapters” tab and double click on the Fastcom device listed in that
class. Verify that the Device Status box on the General class lists “The device is working properly.”.
3. The Fastcom ports did not install correctly. Open the Device Manager (Start -> Run -> devmgmt.msc ->
OK). Expand the “Ports (COM & LPT)” class and double click on the Fastcom ports listed in that class.
Verify that the Device Status box on the General tab lists “The device is working properly.”.
4. The loop back plug is not connected to the correct port/cable.

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Fastcom®: G422/X-PCIe
FASTCOM SERIALFC SETTINGS
Clock Generator Frequency
The clock generator frequency divided by the sampling rate will directly determine the maximum available
bit rate that you may use with the Fastcom board. It works like this: Windows must be able to divide the
clock frequency by the sampling rate and then by any whole number and get to your bit rate as the
answer. By default, the clock is set to 14.7456 MHz (14745600 Hz). This frequency can be divided by
whole numbers to get all of the standard bit rates (i.e. 9600, 19200, 115200, etc). Minimum = 6 MHz,
Maximum = 50 MHz.
For Example: Frequency / Sampling rate (8 or 16) / n = bit rate
14,745,600 / 16 / 96 = 9600
This setting is global. Changing the clock generator frequency will affect all Fastcom ports on the board.
Setting the clock for one port will set it for all ports on the same board.
Echo Cancel
When configured to operate on a 485 network, the card’s receive and transmit lines are tied together to
make a single data line. Because of this, every time data is transmitted out of the port, it will
simultaneously be received on the same port. Enabling Rx Echo Cancel will turn off the receiver during
all transmits, eliminating this simultaneous echo. 485 transmit control must be enabled to use this
feature. This is accomplished in hardware, not software; it will not affect performance.
Sampling Rate
Determines the number of times a data bit is sampled. It can be set to either 4, 8, or 16 on a per-port
basis. It is used in conjunction with the clock generator frequency to determine attainable bit rates. As a
general rule, if your bit rate will be less than or equal to 3.125 Mbits/second, you should use 16 times
sampling. 8 times sampling should only be used if you wish to run at bit rates over 3.125 Mbits/sec.
RS 485
Turns on or off hardware auto 485 direction control. It will automatically de-assert RTS following the last
stop bit of the last character that has been transmitted. This setting affects only the selected port. This is
accomplished in hardware, not software; it will not affect performance.
Turns auto 485 transmitter enable control on or off. The line driver will be enabled at the beginning of a
transmit, and when finished transmitting the line driver will be disabled. This setting affects only the
selected port. This is accomplished in hardware, not software; it will not affect performance.
Rx FIFO Trigger Level1
The Rx FIFO level generates an interrupt whenever the receive FIFO level rises above this preset trigger
level (high water mark). Raising or lowering this value can help to reduce the number of interrupts
generated by the Fastcom port during receives. This setting affects only the selected port. Modify this
value only if necessary in your application or if the receiver is generating too many interrupts for your
CPU to handle.
1The results of changing the Rx FIFO Trigger and Tx FIFO Trigger will depend entirely upon the host PC. What
lowers the number of interrupt requests on one PC will raise the number of interrupt requests on another PC. You
will have to experiment with these values to find the settings that yield the best performance with the lowest
number of interrupt requests that must be serviced by your CPU. If you do not experience problems using the
card in your PC, you should leave these at their default settings.

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Fastcom®: G422/X-PCIe
Tx FIFO Trigger Level1
The Tx FIFO level generates an interrupt whenever the transmit FIFO level falls below this preset trigger
level (low water mark). Raising or lowering this value can help to reduce the number of interrupts
generated by the Fastcom port during transmits. This setting affects only the selected port. Modify this
value only if necessary in your application or if the transmitter is generating too many interrupts for your
CPU to handle. Tx FIFO Trigger + Tx Write Size must not exceed 255.
Custom Speed
When enabled, this allows you to use a non-standard, custom baud rate inside of an application that does
not support custom rates. When this is enabled, the 9600 baud rate will be overridden with the Max Baud
rate. Just select a baud rate of 9600 in your application and you will get whatever rate you have in the
Max Baud field.

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Fastcom®: G422/X-PCIe
FASTCOM: G422/X-PCIE ADAPTER CABLE
We provide access to the individual channels of the FASTCOM: G422/X-PCIe through a shielded CHAMP 68-Pin
connector and an adapter cable (supplied with the board). The adapter cable consists of a CHAMP 68-pin male
plug fanning out to four standard DB9 female receptacles for the 422/4-PCIe and to eight standard DB9 female
receptacles for the 422/8-PCIe.
CHAMP68 Pin Description
4-port cards will only use channels A-D.

13
Fastcom®: G422/X-PCIe
DB9 Pin Description
The FASTCOM: G422/X-PCIe features four (or eight) RS-422/485 channels, which are accessed through the four
(or eight) DB9 connectors on the cable assembly.
The following is a pin description of the DB9 connectors:
PIN NO.
SIGNAL NAME
DIRECTION
1
SIGNAL GROUND (GND)
GROUND
2
READY TO SEND (RTS) +
OUTPUT
3
READY TO SEND (RTS) –
OUTPUT
4
TRANSMIT DATA (TX) +
OUTPUT
5
TRANSMIT DATA (TX) –
OUTPUT
6
CLEAR TO SEND (CTS) -
INPUT
7
CLEAR TO SEND (CTS) +
INPUT
8
RECEIVE DATA (RX) +
INPUT
9
RECEIVE DATA (RX) –
INPUT
Cable
We recommend using vinyl-jacketed, shielded, multiple twisted pair cable (30 AWG
wire) for use with the FASTCOM: G422/X-PCIe. The following cable illustration
shows how to connect two RS-422 devices. Note that disabling handshaking can
eliminate CTS/RTS lines.
TX+
TX-
RTS+
RTS-
CTS+
CTS-
TX+
TX-
RTS+
RTS-
CTS+
CTS-
RX+
RX- RX-
RX+
GND GND

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Fastcom®: G422/X-PCIe
PROGRAMMING
To interface with the serial ports on the Fastcom: G422/X-PCIe in a Windows application, your code will use the
standard Win32 COM API. Documentation pertaining to how to use the Win32 API is beyond the scope of this
document. For more information on using the API, refer to the “Using Communications Resources” in the MSDN.
In addition to the Win32 API, you can also use several special Fastcom-specific commands that allow you to
accomplish all of the options from the Fastcom SerialFC Settings property page. These commands, as well as
the custom structures used in them, are defined in the serialfc.h header file.
Fastcom SerialFC Serial Setting
DeviceIOControl dwIoControlCode
Termination
IOCTL_FASTCOM_{ENABLE, DISABLE}_TERMINATION
Echo Cancel
IOCTL_FASTCOM_{ENABLE,
DISABLE}_ECHO_CANCEL
Sampling Rate
IOCTL_FASTCOM_SET_SAMPLE_RATE
RS 485
IOCTL_FASTCOM_{ENABLE, DISABLE}_RS485
Tx FIFO Trigger Level
IOCTL_FASTCOM_SET_TX_TRIGGER
Tx FIFO Trigger Level
IOCTL_FASTCOM_SET_RX_TRIGGER
Refer to the SerialFC\examples directory on the Fastcom CD or in the downloaded zip file for some example C
programs that demonstrate how to use the Fastcom-specific serial settings as well as providing a general sense
of how to use the Win32 API.

15
Fastcom®: G422/X-PCIe
RS422 / RS485
Most engineers have worked with RS-232 devices at least once in their career. If you have never worked with an
RS-422 or RS-485 device, you will be pleased to know that working with the FASTCOM: G422/X-PCIe is not
much different from working with a standard RS-232 device.
The RS-422 standard was developed to correct some of the deficiencies of RS-232. In commercial and industrial
applications, RS-232 has some significant problems. First, the cable length between RS-232 devices must be
short (usually less than 50 feet at 9600 baud). Second, many RS-232 errors are the result of cables picking up
normal industrial electrical noises such as fluorescent lights, motors, transformers, and other EMF sources. Third,
RS-232 data rates are functionally limited to 19.2K Baud. On the other hand, the newer RS-422 standard makes
cable lengths up to 5000 feet possible and is highly immune to most industrial noises. Data rates are also
improved -- the FASTCOM: G422/X-PCIe features data rates up to 25 Mbits/second. These improvements were
made possible by differentially driving and receiving the data as opposed to the single ended method employed
by the RS-232 standard. With the RS-422 standard, the transmit signal (TX in RS-232) is a differential signal
consisting of TX+ and TX-; the receive signal (RX in RS-232) consists of RX+ and RX-.
Another drawback of RS-232 is that no more than two devices can share a single cable. This is also true of
RS-422, and that's why the RS-485 standard was developed. RS-485 offers all of the benefits of RS-422 and
also allows multiple units (up to 32) to share the same “twisted pair” of wires (see diagram on next page). RS-485
is often referred to as a "multi-drop" or "two-wire, half duplex" network. In order for an RS-485 system to work,
only one driver (transmitter) can occupy the network at a time. This means that each station on the network must
control the enabling/disabling of their drivers in order to avoid network conflicts. If two drivers engage the network
at the same time, data from both will be corrupted. In RS-485 mode, the receivers are always enabled.

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Fastcom®: G422/X-PCIe
Termination Resistance
In both the RS-422 and the RS-485 mode, the receiver end of the cable between two stations must be terminated
with a resistor equal to the characteristic impedance of the wire. This is to prevent signal reflections in the wire
and to improve noise rejection. However, you do not need to add a terminator resistor to your cables when
you use the Fastcom: G422/X-PCIe. The termination resistance is built in.
If you are using the Fastcom: G422/X-PCIe in a multi-drop network, the termination resistor should be disabled
from all units except the first and last (see the RS-485 illustration below). Observe the resistors in the following
drawings and remember that they are built into the Fastcom: G422/X-PCIe (shown below):
Typical RS-422 Installation
Typical RS-485 Installation
1 2
TX
R1 & R2 - Line Termination (100 ohms)
TX+
TX+
TX-
TX- TXRX RX+
RX+
R2
RX-
RX- RX
R1
1
2
4
3
TX
TX
R1 & R2 - Line Termination (100 ohms)
TX+
TX+
TX+
TX+
TX-
TX-
TX-
TX-
TX
TX
RX
RX
RX+
RX+
RX+
RX+
R2
RX-
RX-
RX-
RX-
RX
RX
R1

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Fastcom®: G422/X-PCIe
RS-485 Mode
RS-485 is often referred to as a multi-drop or two-wire, half duplex network because the drivers (transmitters) and
receivers share the same two lines. In fact, up to 32 stations can share the same twisted pair. In order for an
RS-485 system to work, only one driver (transmitter) can occupy the network at a time. This means that each
station on the network must control the enabling/disabling of its drivers in order to avoid network conflicts. If two
drivers engage the network at the same time, data from both will be corrupted. In RS-485 mode, the receivers
are always enabled.
The following cable illustration shows four RS-485 Devices sharing the same twisted pair:
TX+
TX-
RX+
RX -
TX+TX+TX+
TX- TX- TX-
RX+ RX + RX +
RX - RX - RX -
1 2 3 4
Note: The termination resistors from Station #2 and Station #3 have been removed.
Not all RS-422 devices feature RS-485 compatibility; only RS-485 devices can be connected to the RS-485
network.
Note that when in the RS-485 mode, you will need to externally connect TX+ to RX+ and TX- to RX-.

18
Fastcom®: G422/X-PCIe
TECHNICAL SUPPORT
Commtech provides extensive technical support and application suggestions. Most of the problems that may
occur with the FASTCOM: G422/X-PCIe can be corrected by double-checking your cables and your program. We
recommend that you build the loop back plug that is described in the Programming section of this manual. With
that plug, you can quickly isolate the problem to the board, cable, or software.
If you still have unresolved questions, use the following procedure to get technical support:
1. Call our Technical Support Staff at [phone]. They are on duty from 9:00 AM to 5:00 PM Central Time.
2. Ask for technical support for the FASTCOM: G422/X-PCIe. Be ready to describe the problem, your computer
system, your application, and your software.
3. If necessary, our staff will give you an RMA number (Return Material Authorization). Use this number on the
mailing label and in all references to your board. Put the board back in its static bag and in its box. Ship the
board back to us as directed.
4. If you prefer, you may FAX a description of the problem to us at [phone], or we can be reached on the
Internet at http://www.commtech-fastcom.com/TechSupport.html or by email at techsupport@commtech-
fastcom.com.
FASTCOM LIMITED LIFETIME WARRANTY
Commtech’s entire FASTCOM product line is covered by a limited lifetime warranty against defects in workmanship. This
warranty is available only to the original purchaser and only covers defects in our workmanship. Any FASTCOM board that is
returned to Commtech will, at the option of Commtech, be repaired or replaced at no charge -- except for circumstances
excluded by this warranty.
A Return Materials Authorization (RMA) number must be obtained from Commtech before a return will be accepted. Please
contact us via telephone or email to obtain an RMA number.
You are responsible for shipping charges when you return a FASTCOM board to Commtech. We will pay the shipping
charges to send the board back to you if a defect in workmanship is found. However, if no defect in workmanship is found, or
the board is not found to be defective, or any of the following warranty exclusions occur, you will be responsible for shipping
charges both ways.
Warranty Exclusions
This warranty does not cover problems or damage resulting from, but not limited to, the following:
1. Any modification, misuse, abuse, disassembly, misapplication, or unauthorized repair by anyone other than
Commtech.
2. Any improper operation, including any use not in accordance with any verbal product instructions or documentation.
3. Connection to an improper voltage supply or ESD damage.
4. Any other cause not related to workmanship.
Non-Warranty Repairs
We can provide a quote for non-warranty repairs upon request.
If any Commtech product is damaged such that it cannot be repaired, you can return it to Commtech for replacement under
our Non-Repairable Replacement policy, regardless of the cause of damage. Commtech will replace the unit at 60% of the
then-current list price.
Limitation of Liability
Commtech shall not be liable for any special, incidental, indirect, or consequential damages whatsoever, including but not
limited to loss of profits, revenue, or data (whether direct or indirect), or commercial loss for breach of any express or implied
warranty on your product even if Commtech has been advised previously of the possibility of such damages. Commtech does
not warrant that its products will work in every system or every system configuration. We do not warrant that our products will
be suitable for your application. If you are dissatisfied with our product, contact customer service to arrange for a return of our
product and refund of your money. Commtech’s liability, in any case, is limited to the original product purchase price and is
available to the original customer only.

19
Fastcom®: G422/X-PCIe
APPENDIX A
17V354 & 17V358
UART
Data Sheet