Installation guide

4-7
Fast Flush (only flush local buffer)
(1) We have added one optional “Fast Flush” function in our new NPort
Real COM driver. NPort Management Suite for 1 G NPort adds this
function after version 3.2.
(2) For some applications, the user’s program will use the Win32
“PurgeComm()” function before it reads or writes data. With our
design, after the program uses this PurgeComm() function, the NPort
driver will keep querying NPort firmware buffer, rather than just
flushing the local buffer. This kind of design is used because of some
special considerations. However, it might take more time (about
several hundred milliseconds) than a native COM1, because it needs
to work via Ethernet. That’s why the native COM ports on the
motherboard can work fast with this function call, but NPort requires
much more time. In order to accommodate other applications that
require a faster response time, the new NPort driver implements a new
“Fast Flush” option. Note that by default, this function is disabled.
(3) To begin with make sure there are some “PurgeComm()” functions
being used in your application program. In this kind of situation, you
might find that your NPort exhibits a much poorer operation
performance than when using the native COM1 port. Once you have
enabled the “Fast Flush” function, you can check to see if there has
been an improvement in performance.
(4) By default, the optional “Fast Flush” function is disabled. If you
would like to enable this function, from the “Real COM Installer”,
double click on the COM ports that are mapped to the NPort, and then
select the “Fast Flush” checkbox. You should find that when “Fast
Flush” is enabled, the NPort driver will work faster with
“PurgeComm().”
3. Click on the Map to drop down window and
then select the new COM number (COM6 for
the example shown here), and then click OK.
4. You will now be
able to view the
new COM port
number in the Real
COM Installer
window. To save the setting, select Save Configuration under the Server
menu, or click on the Save all Servers icon (the leftmost icon).