NI-Serial Software (USB) for Windows 2000/XP v1.1.1 

Driver Version 1.1.1 
Firmware version 1.1.0

Supporting: 

USB-232
USB-232/2
USB-232/4
USB-485
USB-485/2
USB-485/4

Copyright 2003 National Instruments Corporation.
All Rights Reserved.

New for this release:
 - Fixed a problem that caused write IRPs to be completed improperly under certain rare timing conditions.

--

Please review the following important notes regarding the NI-Serial (USB)
Software and Hardware 

1.  The User Manual and License Information
2.  NISerial.h header file
3.  Installing NI-VISA
4.  Using COM ports greater than COM10 with 'CreateFile' and the Win32 API
5.  Notes on using Auto232
6.  RS-485 transceiver mode support with NI-VISA
7.  Performance under Windows XP
8.  Enumeration problems when using third-party USB 2.0 drivers
9.  Other enumeration problems
10. AMD 756-Based Motherboards and Windows XP
11. Dual-boot systems
12. Connecting devices in USB tiers 5, 6, and 7
13. Contacting National Instruments

--

1. The User Manual

The User Manual and License Agreement are available in electronic format,
and are installed during the software/driver installation.  They are
located in the destination directory (usually \Program Files\National
Instruments\NI-Serial\USB), and may require Adobe Acrobat reader.  Adobe
Acrobat reader can either be installed either from the installation CD
(located under Acrobat Reader) or www.adobe.com.

The User Manual contains detailed information about installing, configuring,
troubleshooting, and using your NI-Serial Software and Hardware.  In
addition, the user manual contains serial communication reference
information.  

The License Agreement, contained on the CD, contains the terms of use for
the NI-Serial (USB) Software.

2. NISerial.h header file

In addition to supporting the Win32 COM API, your NI-Serial (USB) product
has advanced features that can be programmatically controlled.  The
NISerial.h header file is included on this CD and can be used to easily
incorporate the advanced features of your NI-Serial product into 
applications written in C/C++.  For more information about the advanced
features supported by your product, see the User Manual.

3. Installing NI-VISA

If you do not already have NI-VISA 2.6.1 installed, for convenience it is 
available on the installation CD. For additional information regarding 
newer versions of NI-VISA, please check the NI.COM website.  

4. Using COM ports greater than COM10 with 'CreateFile' and the Win32 API

In C, the function 'CreateFile' from Microsoft's Win32 API will fail for
port names COM10 and greater. To be able to use these ports and for the
function to succeed, append the string "\\.\" before the port name.  For
example, to open COM10 use the string "\\\\.\\COM10" for the port name
(doubling the backslashes as per C language syntax).

5. Notes on using Auto232

The Auto232 mode of operation allows you to connect to either a RS-232 DTE
or DCE device using either a null-modem or straight-through cable.  The
USB-232 port will automatically switch approximately every 250 ms between
DTE and DCE operating modes until at least one RS-232 receiver line (RX,
CTS, DSR, RI, or DCD) has a valid voltage.  Auto232 is available on the 
USB-232/2 and USB-232/4, and is not available on the USB-232 (single port).

Not all devices and applications can take advantage of this feature:
 
- Some devices can generate valid voltages on receive lines for both modes,
  even though the device itself is only DTE or DCE.  Thus these devices may
  not operate correctly when using Auto232 mode. 
- Some applications immediately start communicating after a COM port is
  open, thus not allowing enough time for the proper operating mode to be
  selected.  
- Some cabling schemes short RI, DCD, and DSR together.  While this does
  not present a problem in DTE mode, these signals are driven when in DCE
  mode.  Thus by shorting the signals together, the outputs will be double
  (or triple) driven which may cause signal noise or other artifacts.  A 
  straight-through cable should be used instead.

If problems with Auto232 can not be resolved, set the USB-232 to the correct
mode (DTE or DCE) for your device and application.  By default the USB-232
ports are set to DTE mode.
      
6. RS-485 transceiver mode support with NI-VISA

RS-485 transceiver (wire) modes are not fully supported in NI-VISA version
2.6.1 or earlier.  In order to set the desired operating mode, set the
RS-485 transceiver (wire) mode in the Device Manager, and the desired mode
will be set when the VISA resource is opened.  For additional information
regarding the status of NI-VISA, please contact National Instruments or look
on the NI.COM website.  

7. System performance under Windows XP
 
Windows XP system performance may be reduced when multiple USB-485 / USB-232
devices are installed.  This can cause slow screen updating (mouse and
window movements) and reduced task switching performance.  This problem is
addressed in Windows XP Service Pack 1.  To obtain Windows XP Service Pack
1, use Windows Update, or contact Microsoft at www.microsoft.com.  

8. Enumeration problems when using third-party USB 2.0 drivers
 
Some third-party USB 2.0 drivers do not properly support composite devices.
If you encounter enumeration problems (not all COM ports appear in the
Device Manager or Diagnostics), and you are using third-party (non-
Microsoft) USB 2.0 host controller drivers and/or USB 2.0 hub drivers, you
may need to update your USB 2.0 drivers.  Contact your USB 2.0 equipment
vendor for the latest drivers.  If a newer version is not available, or you
still encounter problems, you may need to install the Microsoft USB 2.0
driver using the Windows Update.  To do this, complete the following steps:

1.  Open the device manager by right clicking on My Computer and selecting
    Properties > Hardware tab > Device Manager.
2.  Find the USB 2.0 host controller and USB 2.0 hub in the Universal Serial
    Bus controllers section of the device manager.  There may be multiple
    entries for host controllers and hubs, in which case you will need to
    locate the devices using the device driver name (see step 3).
3.  Right click on the USB 2.0 hub and select Properties > Driver tab > 
    Driver Details
4.  Record the name of the driver file name (example: ausb2hub.sys)
5.  Click OK, then OK again to return to the Device Manager
6.  Right click on the USB 2.0 host controller and select Properties > 
    Driver tab > Driver Details
7.  Record the name of the driver file name(s) (example: aehcd.sys,
    ausb2hub.sys, and ausbd.sys)
8.  Click OK, then OK again to return to the Device Manager
9.  Right click on the USB 2.0 hub and select "Uninstall" then click OK
10. Right click on the USB 2.0 host controller and select "Uninstall" then
    click OK
11. Open the Windows File Search (Start > Search > For Files or Folders)
12. Under "Search for files or folders named:" type: *.inf
13. Under "Containing text:" type the name of the hub driver file recorded
    in step 4
14. Under "Look in:" enter the path to your Windows inf directory (example:
    C:\winnt\inf)
15. Click "Search now"
16. Record the name(s) of the inf files that match the search (example: 
    oem6.inf)
17. Open the Windows inf directory using Windows Explorer or My Computer
18. Locate the file from step 16 and rename the extension to .sav
19. Delete the PNF version of the file from step 16 (example: oem6.PNF)
20. Repeat steps 13-19 for each driver file name recorded in steps 4 and 7.
    You may not find any additional inf files in your system.
21. Return to the Device Manager and select Action > Scan for hardware
    changes.
22. The Found New Hardware wizard should appear for the USB 2.0 host
    controller
23. Select cancel
24. In the device manager, confirm that the USB Host Controller appears
    under "Other Devices" with an exclamation mark.
25. Run Windows Update by Start > Windows Update > Scan for updates
26. Under "Driver Updates" a listing for the Microsoft USB Driver should 
    appear under Microsoft Corporation - Other Hardware.  Add this update,
    then select Review and Install Updates > Install now.
27. After installation is complete, select Action > Scan for hardware
    changes in the Device Manager
28. Verify that the Microsoft driver is being used by the USB 2.0 hub and
    host controller by repeating steps 3 and 6 and confirming that the
    Driver provider is listed as Microsoft.

9. Other enumeration problems

A rare condition may occur where the operating system fails to properly
recognize and enumerate USB devices. If the COM number appears in the Device
Manager with a yellow exclamation mark, or with a zero serial number, and
disconnecting and reconnecting the USB-232/485 does not fix the problem,
right click the affected port(s) and select uninstall.  Then reboot your
system and the USB device(s) will enumerate.

10. AMD 756-based motherboards and Windows XP

Windows XP may not properly configure the built-in USB controller on
motherboards based on the AMD 756 chipset.  If you encounter problems under
Windows XP on AMD 756-based motherboards, and installing the latest
motherboard BIOS and operating system drivers does not help, you may need
to use a plug-in PCI USB host controller in your system.  This problem is
not seen under Windows 2000.

11. Dual-boot systems

If you use a dual-boot system (Windows XP and Windows 2000 for example), the
COM ports may enumerate out of order after switching operating systems. This
is due to the fact that the device firmware is downloaded when the device
is first powered.  Since the firmware images for operation under Windows
2000 and Windows XP are different for enumeration purposes, and the USB bus
power may not be cycled during a reboot, it is possible to be running the
incorrect firmware for the current operating system.  This can be fixed by
disconnecting the USB-232 or USB-485 from USB (and disconnecting power on
the USB-485/4) to force the appropriate firmware to be downloaded.  
                
12. Connecting devices in USB tiers 5, 6, and 7

The USB-485/USB-232 may fail to enumerate when plugged into the end of a
long USB hub chain.  a "This device cannot start" message may also appear
in the Device Manager.

USB uses a tier topology where the USB host controller (and root hub) is 
located in the first (highest) USB tier, and each USB hub resides on a lower
tier.  For example, when three USB hubs are chained together and connected
to the USB root hub, the third USB hub resides in the 4th USB tier.  USB
only supports 7 tier levels, thus if any devices (including hubs) reside in
tiers lower than 7, they will not enumerate correctly.  In addition, USB
hardware may contain internal USB hubs (compound) and/or consist of multiple
devices (composite). In this case, the hardware must reside in tiers higher
than 7 for all of the internal components to enumerate correctly.  

The USB-232/2 and USB-485/2 are composite devices, and must be plugged into
a USB hub residing at tier 6 or higher.  The USB-232/4 and USB-485/4 are
compound composite devices, and must be plugged into a USB hub residing at
tier 5 or higher.  The USB-232 and USB-485 (single port) may be plugged 
into a USB hub residing at tier 6 or higher.  

13. Contacting National Instruments

We appreciate communicating with the people who use our products.  We are
also very interested in hearing about the applications you develop using
our products.  There are many different on-line resources available for 
technical support including on-line problem solving, examples, hardware
references.  In addition, National Instruments has offices around the world
available to support you.  For a complete list of offices and available 
resources, please see the User Manual or visit National Instruments at 
ni.com.
 

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