Yes John. Many ways of communicating between two iPads, as long as there is a signal to communicate it with (either through wifi or cellular signal).
You can text via email, using a third-party app or, the easiest is on the pre-installed Messages app. You don't even need a phone number, an email address will do. As long as the person's email address is on your contact list in the Contacts app (pre-installed as well).