Once an SM registers, you can access that SM through the AP it's connected to.
Even before configuring an IP in the SM, this can be done using the Installation Color Code (ICC) feature, if that's enabled on your AP.
See the thread discussing this here.
Also, you can check out the "Zero Touch" configuration webinar that we recently conducted explaining how this feature can help install radios without intervention on the installer's behalf (i.e. the back end systems can handle provisioning and configuration). Explanation of this feature is here, and the brief webinar can be found here.