Just in case some of you are using the Roland Integra-7 sound module (great instrument!) and plan to connect it to your iPad, this is what I did to make it work:
This worked for me immediately when setting up my new Roland Integra7 sound module with the Roland wireless USB Adapter (WNA1100-RL) to work with the Inegra-7 Editor on my iPad and an AirPort Extreme:
1. In the Airport Utility, I clicked on my AirPort Extreme, then chose "Add Wi-Fi Printer" in the Basestation menu on top of the screen.
2. I turned off my other WiFi-printer and chose "First try" to connect to the USB Adapter without having to use any PIN-number.
3. After a minute's waiting, the AirPort Extreme found the USB Adapter and allowed it to connect to my wireless network.
4. Be patient when the iPad app is searching for the Integra-7 (to make it search for it, go to the settings meny and choose "Midi Devices"). After a few seconds, the iPad app will find and connect to the Integra-7.
5. If you quit the iPad app, you will need to connect to the Integra-7 again, unfortunatly. The USB Adapter will remember and connect to your wireless network by itself the next time you turn on the Integra-7.
iMac (27-inch, Late 2012), OS X Mountain Lion (10.8.3), iPad 3, iPhone5