TCP/IP Com Basic Question

[Labviewguru]

I have never been successful in using the TCP/IP functions to open a session to even so much as get content from a website.

Does anyone have an example. I think I am missing some very key elements, and the examples database isn't much help.

In answering, please keep in mind that I have NEVER done anything with TCP/IP. Datasocket is not what I am looking for, because I want to do things more detailed, such as port scanning and listening, etc.

Thank you,

[AIR]

Hi,

to get a content from a website check out:

http://www.mooregoodideas.com/Downloads/Downloads.htm

(or http://www.mooregoodideas.com press MGI Free Downloads)


The WebINet Driver does exactly this. Also lots of other interresting code
on this site...

Regards,

Wiebe.


"Labviewguru" wrote in message
news:50650000000800000079370000-1007855737000@exchange.ni.com...
> I have never been successful in using the TCP/IP functions to open a
> session to even so much as get content from a website.
>
> Does anyone have an example. I think I am missing some very key
> elements, and the examples database isn't much help.
>
> In answering, please keep in mind that I have NEVER done anything with
> TCP/IP. Datasocket is not what I am looking for, because I want to
do
> things more detailed, such as port scanning and listening, etc.
>
> Thank you,

[Ben]

Cool! A chance to help the Guru.

Check-out the Jeffrey Travis book. The sample CD came with examples to access web-pages. The book was a great read with lots of background info and examples.

I hope this helps,

Ben

P.S. Thanks for your frequent answers on this forum.

[Labviewguru]

Ben,

I have the book here, I guess I should sit down and read it.

Thanks for the help.

[Lab Viewer]

Probably the AppNote 160 ("Using LabVIEW with TCP/IP and UDP" [http://zone.ni.com/devzone/conceptd.nsf/webmain/BA7F1D7CE009BE7686256A5B004F335D?OpenDocument]) will be a good companion for tcpex.llb (in lv\examples\comm\ folder).

Generally, is something like this ...

- a TCP communication is between two IP addresses, each one of them having a port assigned for a specific connection (you can do it on the same machine, using as address "localhost" or "127.0.0.1" and two DIFFERENT ports). Try to use port numbers greater then 1024

- the one playing the server role has to LISTEN on a port in order to detect possible incoming communication requests

- the other one (the client) has to CONNECT to server's address and port

- after the communication is estab
lished, each one can send characters to the other (here you should have your own protocol implemented or a standard one (depends what you are trying to do) like HTTP, FTP ... it's something like a little language (for example, if you want to post some data on a web server, you will send a string like "POST something"))

- both client and server can CLOSE the communication at any time

Hope this helps somehow ...