Yes, it is possible. First you have to convert your AP from Standalone mode to Lightweight. You have to get the recovery images to do this conversion given below & follow the link for the procedure.

c1130-rcvk9w8-tar.124-25e.JAP.tar

c1240-rcvk9w8-tar.124-25e.JAP.tar

http://mrncciew.com/2012/10/20/lightweight-to-autonomous-conversion/

Then you should be able to register these AP to your vWLC. Further to that you have to change the AP mode from Local to FlexConnect in order to use these in vWLC environment. Here is some vWLC deployment guide which may help you

http://www.cisco.com/c/en/us/support/docs/wireless/virtual-wireless-controller/113677-virtual-wlan-dg-00.html

Also refer this document for the WLC software versions required for different model of AP.

http://www.cisco.com/c/en/us/td/docs/wireless/compatibility/matrix/compatibility-matrix.html

HTH

Rasika

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