NETDDE Issues

Hi guys,

Another problem for you NETDDE gurus out there. I have a vision system on Windows NT. The vision software is custom built for us by guys in New York. We have a second machine running NT and Intouch V7.0. On the vision NT box, there is an excel spreadsheet that reads Intouch tag values. The vision software then reads the excel spreadsheet (Don't ask me why it's done this way, it sounds crazy to me as well!). Anyway, everything works fine until I upgrade the Intouch PC to W2K and here is where the problem lies.

The Excel spreadsheet might read the intouch tags but then again it might not. If we shut everything down, say a few prays, a bit of cursing and a raindance or two later, it might start to read the tags only to fail again. We restart the services, reboot PCs, all to no avail.

Does anybody out there know the differences between NETDDE on NT versus win 2k. If I understand the differences I might be able to figure out what is going on.

Thanks,

Colm

I saw a similar problem once and found that Win2K SP2 would connect to an NT machine via netdde but Win2K SP3 would not. That might help you if you can get the W2K machine back to SP2. Otherwise you are stuck unless you can upgrade the NT machine to W2K or find some Microsoft fix on their support site.

Sounds like a security issue with NetDDE.

Two things to try, the first is running the NETDDE Application from the startup folder on both machines, and configuring default security for "ALLOW ALL".

Second is to create duplicate accounts (username/password) on both machines with administrator rights, and then again possibly configuring NetDDE for allow all security.

I know that I've had problems with NetDDE failing to start as a service when requested, and often have to resort to explicitly starting it on boot/login.

Good luck.