Some devices won't allow this type of reset from the radio side so as the previous poster said, you may need the MAC of the Ethernet port.
There are a number of ways to get the MAC address of the radio. I'm assuming that the radio is active since you want to connect to it. Many Wi-Fi clients will tell you the MAC of the AP. An example would be Odyssey client manager from Juniper, which costs money but there is a free trial available. You can also download WireShark and look for Beacons. The MAC of the radio is in the header.
To get the MAC of the Ethernet port, just ping the IP of the radio and check you ARP cache (arp -a in Windows). If you don't know the IP, you can ping a range of IP with Angry IP scanner which is free.