How to monitor clients on access point with dhcp disabled?

I'm guessing this is a fairly simple point. Is there a way reliably to monitor clients connected through an access point? Status-->Device list gives a good run-down of devices with current leases on the access point, but I wondered if there was a good way to log devices connected through the router (sys log doesn't seem to contain relevant entries as the dhcp lease & the logs relevant to that are supplied by the primary router).
thanks!