LabVIEW 6.1 real-time data sharing problem

[BobChuck]

I'm trying to get the host to send data to the client. Most of the data is only sent every 30-45 minutes, but there is some simple real-time communication (such as the current time). The network is set up and working (both host and client can ping each other). The software functions when both programs are run on the same machine.

What am I doing wrong?

[Dennis_Knutson]

In order to send the data to a remote pc, you have to specify the address of the remote one. You don't have anything wired to the address input of TCP Open. As shown in the context Help (which I think I recomended you always have open), if you don't wire anything up, it will default to the local computer.

[BobChuck]

I went ahead and wired a constant (for now) to the TCP/IP open connection VI. It still doesn't work. I checked the IP of the target computer, and the address constant I wired is correct. I don't see a place to wire the IP address on any of the other functions. What else am I missing?

[Dennis_Knutson]

You should wire up your error in/error out connections and see what or if any errors are being generated. There's a lot of different lan/wan settings that could be giving you problems such as firewall settings or virus scanners. What about the client program? What is that doing and does that generate any errors?

[BobChuck]

It just sits there, not getting information. i don't know if the problem is the host program or the client program. I'll post the new versions of the code.

[Dennis_Knutson]

I don't know either as you haven't posted the program that is supposed to get the information. Your error connections could also be done a little better. Wire the error out of the TCP Open to the shift register and put the error indicator inside the while loop so that you know if you get any errors while the VI is running

[Ben]

HI Bob,

Thank you for posting the VI's for us to look at!

A couple of notes:

1) On the recieving side, use one TCP/IP read to get the byte count, then use that value to control how many bytes ared in the the second TCP/IP read.

2) Your byte count will be 4 bytes not 3

3) Sent the byte count as a seperate TCP/IP packet. Do not concantentate the two.

4) Last I looked, property nodes did NOT work in a deplyed LV 6.1 RT app.

5) Global variables are OK if they are written only one place. Is that statement true for all of your globals?

I hope this helps,

Ben

[BobChuck]

Update StelcoCommGlobals is the program that gets the information. It is supposed to get the values that Stelco Host Test sends, display them, and copy them into the globals used by the remainder of the (very large) program.

[Dennis_Knutson]

Sorry, missed the other VI. I'll look at it and let you know.

Message Edited by Dennis Knutson on 09-18-2006 01:39 PM

[BobChuck]

I did some error checking and ran the programs on the two network computers. Stelco Host Test.vi gave me error code 42 for TCP Open.vi... Error Code 42 is "bogusError" which is oh-so-helpful. Any advice?