NPort 5600 Series User’s Manual | Configuring Windows Administrator |
Fast Flush (only flush local buffer)
1.We have added one optional “Fast Flush” function in our new NPort Real COM driver. NPort Administrator Suite for 2G NPort adds it after version 1.2.
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’s firmware several times to make sure there is really no data queued in the 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 “NPort Administrator,” double click on the COM ports that are mapped to the NPort, and then select the “Fast Flush” checkbox. You should fnd that when “Fast Flush” is enabled, the NPort driver will work faster with “PurgeComm().”
The Serial Parameter settings shown here are the default settings when the NPort is powered on. However, the program can redefine the serial parameters to different values after the program opens the port via Win 32 API.
After setting the COM Mapping, remember to select Apply Change to save the information in the host system registry. The host computer will not have the ability to use the COM port until after Apply Change is selected.