Hi,
If you are using an AP, then in the ED you must use the Join/Link protocol. Just doing a link will not work, as the AP sets up a table structure based on a successful join/link, and will only send messages to an ED that has join/linked properly.
If you only want to use link rather than join/link then both ends must be an ED.
I suggest you use the Packet Sniffer with an appropriate board and see what's happening on the radio interface to see where the issue is.
Regards
Simon Buchwald
Amatek Design www.amatek.com