As Panic stated, the EDS files are in RSLinx. Not all EDS files are installed by default. I believe there is a tool for installing EDS files, but I don't remember exactly how to get to it (I'm at home now).
The easiest thing to do might just be to reinstall RSLinx and choose a Custom install so that you can pick the extra EDS files to install.
Be careful about installing all of the EDS files. I ran into a problem when I tried to install all the EDS files. It was a pain in the butt to fix too!
OG