tcp port hangs open when crash of program

[wedge87t]

I am using the TCP library to open, write, read, close TCP port 5002.  Everything works great except for when the program crashes (still in dev phase :P) and I don't get a chance to call "DisconnectFromTCPServer" I am not able to reconnect to that port but I can still connect to that host - I assume this is because the port is left open etc.

Is there any way I can force that port to close if its open?

[altenbach]

I am assuming that you mean the client program crashes.

Tell us a little more about that "server". Is this also a LabVIEW program? If so, you can reset the connection after an idle timeout or even design it so it allows multiple concurrent connections to the same port.

[wedge87t]

Yes - this is on the client side using CVI 8.0 TCP Library. 

I am communicating directly with a compumotor 6K controller which is setup as the TCP server with dedicated ports (5001-5004).

Here is exactly what happens:

Good Run

Connect to TCP from client

read & write to server

Disconnect TCP

Able to reconnect next time

Bad Run

Connect to TCP from client

read & write to server

program shutdown or crash so no Disconnect took place

try to run program again - waits and waits to connect to that port - gives timeout

the only way to connect now is to shut down the server or reboot client so again I assume the port is locked?

thanks..

W

[altenbach]

OK, you are on the wrong board. This is LabVIEW, but you're using CVI. The Labwindows/CVI board is over there:

http://forums.ni.com/ni/board?board.id=180

In any case, I think the problem lies entirely with the server, seems to be pretty primitive. Good luck!

[wedge87t]

My bad - but it also happens in Labview.