how to establish a network DDE?

[ndendno78]

Hey,

I would like use dynamic data exchange (DDE) with a software (DaVIs) on a Windows NT computer from a different computer with windows XP. I have checked that the two LabView can send DDE to DaVIs when they both on the same computer. I know I should use the Network DDE between the two computer. I am not so sure about setting the network DDE windows application but I am sure that the service name is "DaVis" and the topic name is "CL".

Does anyone have an idea of how to set Network DDE with Labview?

p.s. - I have read application Note 166, "Using DDE in LabView (Windows only)" but I think that I am missing some steps.

[Brett_B.]

The Network DDE is separate from LabVIEW and must be enabled from the Windows Platform to allow LabVIEW to communicate with applications across a network. The directions for setting up a 9x machine and an NT machine are different but are both found at the bottom of the App note you have referenced. Which step are you having a problem with, or, what are you seeing after completing the procedure.

-Brett

[ndendno78]

Hey Brett,

Thank you for the reply.

The stage that i dont understand is, stage No.3 under the heading "Setting up a NetDDE Server on Windows 2000/NT" in the document I have mentioned.

The procedure I have done was to open DDEshare.exe on the NT machine, create a reg named "DaVis" then I have entered Dacis as the old and new application name and CL as the new and old topic name. On the XP machine I have created the attached file (a vi which suppose to send a command in C programing language to the program DaVIs). As you can see i have entered the following \\prl101.anu.edu.au\ndde$ as the service and DaVIs as the topic.

The response was DDE Open: ERROR 14013 DMLERR_NO_CONV_ESTABLISHED

Thanks again.
Eldad

[Brett_B.]

Eldad,

\\prl101.anu.edu.au\ndde$ is pointing to the machine and the service. On your 2k/NT machine...make sure that you have added and are properly addressing your service. As is now...your "share" is called ndde$....if you don't have one created of this name it would return the error you received. You can add a share by clicking on the Add Shares button under the ddeshare.exe program.

See if that is what it is,

Brett

[ndendno78]

Hey Brett,

I have created a chare NetworkDDE called DaVis& and I also "Trusted it". The service is now: \\prl101.anu.edu.au\DaVis$ and the topic is "CL". However, I still get the same error: DDE Open: DMLERR_NO_CONV_ESTABLISHED.

In the "DDE Open Conversation.vi", the service appear as "\\" and the topic as "CL", whereas I would expect the service to be "DaVis" with the same topic name.

did you have a look at my sand_DaVis.vi? do I need to modify it?

Cheers
Eldad

[Brett_B.]

Eldad,

A couple of things to test:
Try one of the existing shares on your machine and see if you can connect to it....I think Win2k has chat$ and hearts$ by default as trusted shares.
Try using the IP address rather than the computer name...

I was able to connect with another machine in the office using your program...all I did was change the IP address and the share name.

-Brett

[ndendno78]

Brett,

How will I know that i am connected? So far i have open the DaVis application and send a command to it (for instance print a word) but nothing had happen.

could you tell me how did you set up your machines please?

Cheers,

Eldad

[Brett_B.]

I tried until I didn't receive the "NO CONN" error and then I knew I was connected. Have you tried the DDEs that come pre-configured??? hearts$ or chat$?? Those worked for me right off the bat.

-Brett