Serial Communications Redirection over a LAN Connection

[Pat Garret]

Is there anything like an Int14 redirector available for CVI that can
facilitate accessing the serial port of one workstation or server on a LAN
from another workstation? I'd like to be able to use a CVI app that I've
written that uses RS232C serial communications with an instrument located
in a manufacturing area remotely from my office. I know there are
modem-sharing progarms that do something like this but is there a simpler
way under CVI?.

[Jason F.]

You will either have to find a 3rd party tcp/ip server that allows you to connect to a certain port on the remote computer with the serial port you want to use and exposes the functionality with some type of tcp/ip messaging protocol, or write your own server program in CVI, which is relatively easy.

If you go the 3rd party route (which costs you extra money), you will then need to write a client app in CVI that connects to said port and sends the messages required to make the remote machine carryout the serial communications you desire.

If you cannot find a 3rd party application you could very easily write your own server in CVI that when it receives data from the other CVI client app it then does a ComWrite to the serial port and when data is available on the seria
l port the server does a TCP/IPWrite back to the client. You should take a look at the Client and Server examples that ship with CVI in the C:\...\cvi\samples\tcp directoy to get a gist of how to perform the tcp/ip functionality and you can look at the examples in the C:\...\cvi\samples\rs232 directory to understand serial communications in CVI.

Jason F.
Applications Engineer
National Instruments
www.ni.com/ask