For my understanding ABAP Development Tools in eclipse still needs a SAP Gui installation. I am not sure if it can work without it.
Do you have already an OData service running on your ABAP?
Is this OData accessible via a browser within your CAL (where SAP Gui is working)?
Are you behind a company fire-wall (e.g. ping www.google.com cannot resolve the name to an IP address) ?
Regards, Thomas