National Instruments NI-488.2 Software for Windows 3 for the 
GPIB-232CT-A, the GPIB-485CT-A and the GPIB-RF.
Version 2.7. 
Copyright 1995 National Instruments Corporation.
All Rights Reserved.


Thank you for purchasing this GPIB interface and the NI-488.2 software 
for Microsoft Windows 3.


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.  To make it easy for you to communicate with us, Appendix C
in the "NI-488.2 User Manual for Windows" contains forms for you
to complete.  Completing these forms before contacting National Instruments
facilitates communication.


NOTE ABOUT SOFTWARE CONFIGURATION UTILITY
-----------------------------------------

The Windows GPIB software configuration utility no longer resides in the
NI-488.2 GPIB Software group.  It is now a control panel applet accessible 
by running Control Panel in the Main group of the Program Manager.  The
utility, ibconf.cpl, resides in the Windows system directory. 


NOTE FOR RUNNING WIN32S GPIB APPLICATIONS
-----------------------------------------

The NI-488.2 software for Windows includes two dynamic link libraries (DLLs)
that make it possible to run 32-bit Windows GPIB applications. The two 
DLLs are called GPIB-32.DLL and GPIB-16.DLL. The 32-bit DLL (GPIB-32.DLL)
uses the Universal Thunking mechanism to communicate with the 16-bit DLL
(GPIB-16.DLL), and the 16-bit DLL talks directly to the standard 16-bit
GPIB DLL (GPIB.DLL) to get it to execute the appropriate NI-488.2 function.
For more information on the Universal Thunking mechanism, refer to Microsoft's 
"Win32s Programmer's Reference", chapter 4, "Universal Thunk".

When the NI-488.2 software for Windows is installed, these two DLLs are copied 
into the Windows SYSTEM directory.  You can use the Win32s Interactive
Control utility, a Win32s version of the Win16 Interactive Control
utility, to verify that the two DLLs are functioning properly.

In order to run the Win32s Interactive Control utility, you must have 
Microsoft Win32s support installed on your system. The Win32s Interactive
Control icon is the National Instruments eagle, like the Win16 Interactive
Control icon.

Anyone interested in developing 32-bit Windows applications should
contact National Instruments to obtain information about ordering the 
NI-488.2M Software for Windows NT package. It includes the language
interface and documentation necessary for developing 32-bit GPIB Windows
applications.


NOTE FOR LABVIEW USERS
----------------------

LabVIEW includes icons for WIBConf and WIBIC in the LABVIEW group when it
is installed. Please delete these two program items from the LABVIEW
group. The WIBConf program item in the LABVIEW group cannot be used to
configure the NI-488.2 software. The GPIB configuration utility is now a
control panel applet and must be run from the control panel. The
replacement for the WIBIC program item is the Win16 Interactive Control
program item in the NI-488.2 GPIB Software group. 


NOTE ABOUT SERIAL CONTROLLER CHIPS
----------------------------------

Though the GPIB-232/485CT-A supports serial baud rates up to 38400, the 
type of hardware your PC is equipped with affects the maximum baud 
rate you can use.  The serial controller chip in the PC is called a 
Universal Asynchronous Receiver/Transmitter (UART).  There are two 
types of UARTs in common use on PCs:  the 8250/16450 and the 16550.
The difference between these two types of UARTs is that the 16550 UART
has FIFOs that can store more information before an interrupt to the
computer's processor is necessary, while the 8250/16450 UART has no FIFOs
and must interrupt the processor to service each byte sent or received. 
Because of Windows system overhead, sustained communications above 9600
baud are not possible with 8250/16450 UARTs.  With few exceptions,
transfers using baud rates up to and including 38400 can be sustained in
Windows if a 16550 UART is used.

To determine the type of UART your system has, use Microsoft Diagnostics
(shipped with new versions of DOS) and refer to the COM Ports information
reported.  Some new PCs are shipped with 16550 UARTs, and plug-in COM cards
are available which use the 16550 UART.


NOTE ABOUT MULTIPLE APPLICATIONS
--------------------------------

Due to limitations with Windows' COM functions, you cannot run more than
one application using a board or a device attached to that board
simultaneously.  For example, assume you want to use an application which
opens DEV2 (attached to GPIB0) and the Win16 Interactive Control program 
using GPIB0.  If you launch Win16 Interactive Control and open GPIB0, 
perform GPIB operations, then, without placing GPIB0 offline, run the other
application which opens DEV2 (attached to GPIB0), you will not be able
to use the open descriptor in the Win16 Interactive Control program again.
To use a GPIB0 descriptor in the Win16 Interactive Control program again,
a new descriptor will need to be opened.
